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 A115654 #4 Aug 24 2012 10:59:35 %S A115654 4,6,9,10,14,15,21,25,26,49,51,57,58,62,65,69,74,77,106,111,115,118, %T A115654 119,121,122,123,129,133,134,155,158,159,161,166,169,177,178,386,393, %U A115654 394,395,398,403,407,411,413,437,445,446,447,451,453,458,489,493,497 %N A115654 Semiprimes (A001358) which are the sum of distinct double factorials (A006882). %C A115654 Double factorials 0!! and 1!! are not considered distinct. Note that double factorial (n!!) is different from (n!)!. %e A115654 384 = 2*19 = 8!!+2!!. %t A115654 Union[Select[Total/@Subsets[Range[10]!!,10],PrimeOmega[#]==2&]] (* _Harvey P. Dale_, Aug 24 2012 *) %Y A115654 Cf. A006882, A001358, A115651, A115652, A115653. %K A115654 nonn %O A115654 1,1 %A A115654 _Giovanni Resta_, Jan 28 2006