cp's OEIS Frontend

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.

A032788 Numbers k such that k(k+1)(k+2)...(k+19) / (k+(k+1)+(k+2)+...+(k+19)) is an integer.

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%I A032788 #25 Nov 20 2024 16:06:08
%S A032788 0,1,3,4,7,8,10,13,15,16,18,19,22,23,28,29,31,33,36,38,40,43,49,50,51,
%T A032788 53,57,58,62,64,67,73,75,76,78,84,85,88,95,101,103,106,112,113,114,
%U A032788 118,127,128,133,135,139,148,152,153,166,169,171,172,178,183,190
%N A032788 Numbers k such that k(k+1)(k+2)...(k+19) / (k+(k+1)+(k+2)+...+(k+19)) is an integer.
%C A032788 (d-19)/2 where d >= 19 divides 85734032330071125. In particular, the sequence is finite. - _Robert Israel_, Jul 13 2018
%H A032788 Robert Israel, <a href="/A032788/b032788.txt">Table of n, a(n) for n = 1..8739</a>
%p A032788 sort([seq((t-19)/2, t=select(`>=`,numtheory:-divisors(85734032330071125),19))]); # _Robert Israel_, Jul 13 2018
%t A032788 Select[Range[0,190],IntegerQ[Times@@Range[#,#+19]/Total[Range[#,#+19]]]&] (* _Harvey P. Dale_, Sep 02 2016 *)
%t A032788 Select[Range[0,190],With[{c=Range[#,#+19]},Mod[Times@@c,Total[c]]==0&]] (* _Harvey P. Dale_, Nov 20 2024 *)
%Y A032788 Cf. A032765-A032798.
%K A032788 nonn,fini,full
%O A032788 1,3
%A A032788 _Patrick De Geest_, May 15 1998
%E A032788 Definition corrected by _Harvey P. Dale_, Sep 02 2016
%E A032788 Offset changed by _Robert Israel_, Jul 13 2018