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 A101977 #9 May 30 2012 02:53:31
%S A101977 1,2,3,5,7,11,15,22,31,43,58,74,97,131,171,222,277,349,447,564,698,
%T A101977 868,1074,1321,1601,1967,2398,2911,3513,4235,5083,6071,7242,8637,
%U A101977 10229,12102,14293,16848,19802,23271,27276,31846,37132,43196,50191,58238,67425,77946
%N A101977 Number of products of distinct factorials not exceeding n!.
%C A101977 a(n) is the position of n! in A058295 (products of distinct factorials). a(n) < A101976(n) for n > 2 and a(n) > A101978(n) for n > 10.
%H A101977 <a href="/index/Fa#factorial">Index entries for sequences related to factorial numbers.</a>
%e A101977 a(4) = 5 because 5 products of distinct factorials do not exceed 4!, namely, 1, 2, 6, 12 and 24.
%t A101977 d[k_] := (m=1; With[{p=With[{s=Subsets[Table[n!, {n, k}]]}, Sort[Table[Apply[Times, s[[n]]], {n, Length[s]}]]]}, While[p[[m]]<=k!, m++ ]; Length[Union[Take[p, m-1]]]]);Table[d[k], {k, 19}]
%Y A101977 Cf. A000142, A058295, A101976, A101978.
%K A101977 nonn
%O A101977 1,2
%A A101977 _Jonathan Sondow_, Dec 22 2004
%E A101977 a(20)-a(48) from _Donovan Johnson_, May 30 2012