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.

A246854 Numbers n such that sigma(n+4) - sigma(n) = n + 4.

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%I A246854 #18 Sep 08 2022 08:46:09
%S A246854 1,4,26,122,146,458,746,3746,47612,16065500,388978292,5313509288,
%T A246854 64278616556
%N A246854 Numbers n such that sigma(n+4) - sigma(n) = n + 4.
%C A246854 Also numbers n such that A001065(n+4) = A000203(n). - _Michel Marcus_, Sep 06 2014
%C A246854 a(14) (if it exists) > 10^11. - _Hiroaki Yamanouchi_, Sep 10 2014
%C A246854 a(14) (if it exists) > 10^13. - _Giovanni Resta_, Jul 13 2015
%e A246854 Number 26 is in sequence because sigma(26+4) - sigma(26) = 72 - 42 = 30 = 26 + 4.
%o A246854 (Magma) [n:n in[1..10^7] | SumOfDivisors(n+4)-SumOfDivisors(n) eq n+4]
%o A246854 (PARI)
%o A246854 for(n=1,10^7,if(sigma(n+4)-sigma(n)==n+4,print1(n,", "))) \\ _Derek Orr_, Sep 05 2014
%Y A246854 Cf. A000203, A067816, A246851, A246852, A246853, A246855.
%K A246854 nonn,more
%O A246854 1,2
%A A246854 _Jaroslav Krizek_, Sep 05 2014
%E A246854 a(10)-a(13) from _Hiroaki Yamanouchi_, Sep 10 2014