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 A115651 #5 Mar 30 2012 17:40:35 %S A115651 1,4,8,9,16,25,27,49,64,72,108,121,125,128,169,392,400,432,441,500, %T A115651 512,961,968,972,1125,1331,1352,1444,3844,3888,3969,4225,4232,4356, %U A115651 4900,4913,5184,5292,5324,10404,10800,10952,11449,11881,14283,14400 %N A115651 Powerful(1) numbers (A001694) which are the sum of distinct double factorials (A006882). %C A115651 Double factorials 0!! and 1!! are not considered distinct. Note that double factorial (n!!) is different from (n!)!. %H A115651 <a href="/index/Pow#powerful">Index entries for sequences related to powerful numbers</a> %e A115651 392 = 2^3*7^2 = 8!! + 4!!. %Y A115651 Cf. A001694, A006882, A115652, A115653, A115654. %K A115651 nonn %O A115651 1,2 %A A115651 _Giovanni Resta_, Jan 28 2006