This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A125309 #4 Jul 14 2012 11:41:10 %S A125309 4,25,76,125,187,255,437,629,1152,1276,1298,1352,1617,1668,2337,3363, %T A125309 3618,4116,4439,5891,6432,8279,11178,13125,14144,14812,14824,18647, %U A125309 22165,22466,23472,24727,24743,25631,26128,32978,37329,42983,48442 %N A125309 Numbers n such that twice the sum of the prime factors of n equals the product of the digits of n. %C A125309 Number of terms less than 10^n: 1, 3, 8, 22, 48, 103, 230, 611, ...; number of odd terms less than 10^n: 0, 1, 6, 12, 21, 51, 120, 331, ..., . - _Robert G. Wilson v_, Dec 12 2006 %e A125309 Prime factors of 76 are 2 and 19; twice their sum is 42 which the product of 7 and 6 - the digits of 76. %t A125309 Select[Range[2, 20000], Times @@ IntegerDigits[ # ] == 2 Plus @@ Transpose[FactorInteger[ # ]][[1]] &] %Y A125309 Similar to A067173 = numbers n such that the sum of the prime factors of n equals the product of the digits of n. %K A125309 base,nonn %O A125309 1,1 %A A125309 _Tanya Khovanova_, Dec 10 2006 %E A125309 More terms from _Robert G. Wilson v_, Dec 12 2006