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%I #9 May 30 2012 02:53:43
%S 1,2,4,8,15,28,49,83,134,209,317,473,687,987,1403,1972,2732,3752,5096,
%T 6852,9144,12113,15919,20802,27012,34860,44755,57136,72592,91802,
%U 115567,144916,180963
%N Number of products of factorials not exceeding n!.
%C a(n) is the position of n! in A001013 (Jordan-Polya numbers: products of factorials). a(n) > A101977(n) for n > 2 and a(n) > A101978(n) for n > 3.
%H <a href="/index/Fa#factorial">Index entries for sequences related to factorial numbers.</a>
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/FactorialProducts.html">Factorial Products</a>
%e a(4) = 8 because 8 products of factorials do not exceed 4!, namely, 1, 2, 4, 6, 8, 12, 16 and 24.
%t m[n_]:=(For[p=0; a=f=Table[k!, {k, 1, n}], p=!=a, p=a;a=Select[Union@@Outer[Times, f, a], #<=n!&]];a);Table[Length[m[n]], {n, 20}]
%Y Cf. A000142, A001013, A101977, A101978.
%K nonn
%O 1,2
%A _Jonathan Sondow_, Dec 22 2004
%E a(21)-a(33) from _Donovan Johnson_, May 30 2012