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.

A328784 Integers k such that the k-th prime divides the k-th Lucas number.

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%I A328784 #34 Sep 08 2022 08:46:24
%S A328784 2,4,5,608,1221,60264,205965,994856,69709961,3140421767
%N A328784 Integers k such that the k-th prime divides the k-th Lucas number.
%p A328784 a:= 1:
%p A328784 b:= 2:
%p A328784 p:= 2:
%p A328784 Res:= NULL:
%p A328784 for n from 2 to 10^6 do
%p A328784   c:= a+b;
%p A328784   b:= a;
%p A328784   a:= c;
%p A328784   p:= nextprime(p);
%p A328784   if a mod p = 0 then
%p A328784     Res:= Res,n;
%p A328784   fi
%p A328784 od:
%p A328784 Res; # _Robert Israel_, Oct 30 2019
%o A328784 (Magma) [n: n in [1..100000] | IsZero(Lucas(n) mod NthPrime(n))];
%Y A328784 Cf. A000032, A000040.
%Y A328784 Cf. A075702 (analog with Fibonacci).
%K A328784 nonn,more
%O A328784 1,1
%A A328784 _Juri-Stepan Gerasimov_, Oct 30 2019
%E A328784 a(8) from _Robert Israel_, Oct 30 2019
%E A328784 a(9)-a(10) from _Daniel Suteu_, Nov 07 2019