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 A115646 #2 Mar 30 2012 17:40:35
%S A115646 6,9,25,26,33,121,122,123,129,145,146,721,723,745,746,753,841,842,843,
%T A115646 849,865,866,871,5041,5042,5065,5071,5161,5163,5169,5186,5191,5761,
%U A115646 5767,5793,5905,5906,5911,40321,40322,40323,40345,40346,40353,40441
%N A115646 Semiprimes (A001358) that are sums of distinct factorials.
%C A115646 Factorials 0! and 1! are not considered distinct.
%e A115646 721 = 6!+1! = 7*103.
%t A115646 semipQ[n_] := Plus @@ Last /@ FactorInteger[n] == 2; fac=Range[10]!;lst={}; Do[ n = Plus@@(fac*IntegerDigits[k, 2, 10]); If[semipQ[n], AppendTo[lst, n]], {k, 2^10-1}]; Union[lst]
%Y A115646 Cf. A001358, A025494, A115645, A115644, A089359.
%K A115646 nonn
%O A115646 1,1
%A A115646 _Giovanni Resta_, Jan 27 2006