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 A158989 #2 Mar 30 2012 17:37:48 %S A158989 1,54,62,4190,4920,10538,12376,16065,16732,26345,37236,47026,48323, %T A158989 53480,56712,58520,61209,62337,65163,83720,84135,94520,100980,126238, %U A158989 135266,141078,143726,146910,147354,154238,174217,183505,185334,207328 %N A158989 Numbers n such that product of double factorials of the digits of n equals sigma(n). %e A158989 sigma(444119)=4!!*4!!*4!!*1!!*1!!*9!!, so 444119 is in the sequence. %t A158989 Select[Range[210000],DivisorSigma[1,# ]==Apply[Times,IntegerDigits[ # ]!! ]&] %Y A158989 Cf. A137603, A158990, A158991, A158992. %K A158989 base,easy,nonn %O A158989 1,2 %A A158989 _Farideh Firoozbakht_, Jul 07 2009