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 A375638 #7 Aug 22 2024 09:17:49 %S A375638 1,2,3,4,5,17,42,43,138,125,220,33,387,1766,3269,7014,1398,1399,1958, %T A375638 19143,30759 %N A375638 a(n) is the least positive integer k such that k! has exactly n infinitary divisors that are factorials, or -1 if no such number exists. %C A375638 a(n) is the least k > 0 such that A375636(k) = n. %e A375638 The n values m(i) such that m(i)! is an infinitary divisor of a(n)! for n = 1..12 are: %e A375638 n | a(n) | m(i), i = 1..n %e A375638 ---+------+----------------------------------------- %e A375638 1 | 1 | 1 %e A375638 2 | 2 | 1, 2 %e A375638 3 | 3 | 1, 2, 3 %e A375638 4 | 4 | 1, 2, 3, 4 %e A375638 5 | 5 | 1, 2, 3, 4, 5 %e A375638 6 | 17 | 1, 2, 6, 15, 16, 17 %e A375638 7 | 42 | 1, 2, 3, 4, 5, 6, 42 %e A375638 8 | 43 | 1, 2, 3, 4, 5, 6, 42, 43 %e A375638 9 | 138 | 1, 2, 3, 4, 5, 6, 7, 8, 138 %e A375638 10 | 125 | 1, 2, 3, 4, 5, 6, 7, 8, 124, 125 %e A375638 11 | 220 | 1, 2, 3, 4, 5, 6, 7, 8, 218, 219, 220 %e A375638 12 | 33 | 1, 2, 3, 4, 5, 6, 28, 29, 30, 31, 32, 33 %Y A375638 Cf. A000142, A037445, A077609, A375635, A375636. %K A375638 nonn,more %O A375638 1,2 %A A375638 _Amiram Eldar_, Aug 22 2024