Rabu, 22 Mei 2013

Ruth-Aaron Pair

Whoa, what is Ruth-Aaron Pair?
That is the first thing that crossed my mind when I saw it at wikipedia.

Well, after I read it, I came to this conclusion:

Ruth-Aaron pair consists of two consecutive integers (e.g. 135 and 136) for which the sums of the prime factors of each integer are equal. For example :

77 = 7 x 11
78 = 2 x 3 x 13

and

7 + 11 = 2 + 3 + 13 = 18

If only distinct prime factors are counted, the first few Ruth–Aaron pairs are:
(5, 6), (24, 25), (49, 50), (77, 78), (104, 105), (153, 154), (369, 370), (492, 493), (714, 715), (1682, 1683), (2107, 2108), (2299, 2300), (2600, 2601), (2783, 2784), (5405, 5406), (6556, 6557), (6811, 6812), (8855, 8856), (9800, 9801), (12726, 12727), (13775, 13776), (18655, 18656), (21183, 21184), (24024, 24025), (24432, 24433), (24880, 24881), (25839, 25840), (26642, 26643), (35456, 35457), (40081, 40082), (43680, 43681), (48203, 48204), (48762, 48763), (52554, 52555), (61760, 61761), (63665, 63666), (64232, 64233), (75140, 75141)

If counting repeated prime factor (e.g. 8 = 2 x 2 x 2 and 9 = 3 x 3; 2 + 2 + 2 = 3 + 3), the first few Ruth–Aaron pairs are:
(5, 6), (8, 9), (15, 16), (77, 78), (125, 126), (714, 715), (948, 945), (1330, 1331), (1520, 1521), (1862, 1863), (2491, 2492), (3248, 3249), (4185, 4186), (4191, 4192), (5405, 5406), (5560, 5561), (5959, 5960), (6867, 6868), (8280, 8281), (8463, 8464), (10647, 10648), (12351, 12352), (14587, 14588), (16932, 16933), (17080, 17081), (18490, 18491), (20450, 20451), (24895, 24896), (26642, 26643), (26649, 26650), (28448, 28449), (28809, 28810), (33019, 33020), (37828, 37829), (37881, 37882), (41261, 41262), (42624, 42625), (43215, 43216)

The intersection of the two lists begins:
(5, 6), (7,7, 78), (714, 715), (5405, 5406), (26642, 26643), (52554, 52555), (95709, 95710), (154842, 154843), (173162, 173163), (204258, 204259), (208581, 208582), (248109, 248110), (278277, 278278), (332994, 332995), (417162, 417163), (445305, 445306), (529194, 529195), (554682, 554683), (693610, 693611), (851709, 851710), (869054, 869055), (1232746, 1232747), (1252509, 1252510), (1275546, 1275547), (1275730, 1275731), (1549454, 1549455), (1600962, 1600963), (1607045, 1607046), (1671333, 1671334), (1672710, 1672711), (1777026, 1777027)


Ruth-Aaron Triplets also exist.
If only distinct prime factors are counted :
89460294 = 2 × 3 × 7 × 11 × 23 × 8419
89460295 = 5 × 4201 × 4259
89460296 = 2 × 2 × 2 × 31 × 43 × 8389
2 + 3 + 7 + 11 + 23 + 8419 = 5 + 4201 + 4259 = 2 + 31 + 43 + 8389 = 8465

151165960539 = 3 × 11 × 11 × 83 × 2081 × 2411
151165960540 = 2 × 2 × 5 × 7 × 293 × 1193 × 3089
151165960541 = 23 × 29 × 157 × 359 × 4021
3 + 11 + 83 + 2081 + 2411 = 2 + 5 + 7 + 293 + 1193 + 3089 = 23 + 29 + 157 + 359 + 4021 = 4589

If counting repeated prime factor:
417162 = 2 × 3 × 251 × 277
417163 = 17 × 53 × 463
417164 = 2 × 2 × 11 × 19 × 499
2 + 3 + 251 + 277 = 17 + 53 + 463 = 2 + 2 + 11 + 19 + 499 = 533

6913943284 = 2 × 2 × 37 × 89 × 101 × 5197
6913943285 = 5 × 283 × 1259 × 3881
6913943286 = 2 × 3 × 167 × 2549 × 2707
2 + 2 + 37 + 89 + 101 + 5197 = 5 + 283 + 1259 + 3881 = 2 + 3 + 167 + 2549 + 2707 = 5428

Until 2006, just 4 above triplets are known.

Source : http://en.wikipedia.org/wiki/Ruth%E2%80%93Aaron_pair

2 komentar:

  1. mmm ... just already think to write this kind, amazing number of math ... hahahaha ...
    but the more amazing thing was still FIBONACCI number ... gosh ...

    BalasHapus
  2. hahahahaha..
    Math is amazing. A lot of thing should be writen if I choose Fibonacci number.. :p

    BalasHapus