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 A109640 #15 Aug 09 2025 07:47:54
%S A109640 1,2,5,11,13,19,23,31,47,97,101,113,131,151,181,227,307,457,907,1009,
%T A109640 1129,1289,1511,1801,2251,3001,4507,9001,10007,11251,12889,15013,
%U A109640 18013,22501,30011,45007,90001,100003,112501,128591,150001,180001,225023,300007,450001
%N A109640 Indices of records in A109631.
%C A109640 Previous name was: Values of k which are incrementally the largest values of the function: Smallest number m such that k divides (10's complement factorial of m).
%p A109640 A089186 := proc(n) 10^max(1,ilog10(n)+1)-n ; end: A110396 := proc(n) mul( A089186(i),i=1..n) ; end: A109631 := proc(n) local a; for a from 1 do if A110396(a) mod n = 0 then RETURN(a) ; fi ; od: end: A109640 := proc(n) option remember ; local nprev,aprev,a ; if n = 1 then RETURN(1); else nprev := A109640(n-1) ; aprev := A109631(nprev) ; for a from nprev+1 do if A109631(a) > aprev then RETURN(a) ; fi ; od; fi ; end: for n from 1 do printf("%d, ",A109640(n)) ; od: # _R. J. Mathar_, Feb 12 2008
%Y A109640 Cf. A002034, A109631, A110396.
%K A109640 nonn,base
%O A109640 1,2
%A A109640 _Jason Earls_, Aug 04 2005
%E A109640 More terms from _R. J. Mathar_, Feb 12 2008
%E A109640 a(23)-a(45) from _Jinyuan Wang_, Aug 09 2025
%E A109640 New name (using comment from _R. J. Mathar_) from _Joerg Arndt_, Aug 09 2025