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 A115648 #2 Mar 30 2012 17:40:35 %S A115648 1,4,9,16,25,49,64,121,169,400,441,961,1444,3844,3969,4225,4356,4900, %T A115648 5184,10404,11449,11881,14400,15625,47089,47524,56644,57600,139129, %U A115648 145924,149769,182329,192721,695556,705600,792100,837225,2073600 %N A115648 Square numbers which are the sum of distinct double factorials (A006882). %C A115648 Double factorials 0!! and 1!! are not considered distinct. Note that double factorial (n!!) is different from (n!)!. %e A115648 10404 = 102^2 = 1!! + 4!! + 11!!. %Y A115648 Cf. A006882, A115649, A115650, A115651, A025494. %K A115648 nonn %O A115648 1,2 %A A115648 _Giovanni Resta_, Jan 28 2006