cp's OEIS Frontend

A270532 Integers k such that A003266(p) is not divisible by p*(p+1)/2 where p is the k-th prime.

%I A270532 #16 May 15 2021 12:36:37
%S A270532 1,2,4,9,14,19,23,27,31,38,39,48,49,61,73,76,86,90,91,93,96,99,101,
%T A270532 107,111,117,118,124,129,138,143,144,150,153,154,155,161,166,179,188,
%U A270532 192,195,208,213,217,219,224,229,236,243,247,250,253,258,261,262,269,272,276,277,283,285,292,300
%N A270532 Integers k such that A003266(p) is not divisible by p*(p+1)/2 where p is the k-th prime.
%C A270532 See A000057 to corresponding prime numbers. In other words, this sequence is an indirect way to generate primes dividing all Fibonacci sequences.
%H A270532 Michel Marcus, <a href="/A270532/b270532.txt">Table of n, a(n) for n = 1..1000</a>
%o A270532 (PARI) f(n) = prod(k=1, n, fibonacci(k)); \\ A003266
%o A270532 isok(n) = (lift(Mod(f(prime(n)),(prime(n)*(prime(n)+1)/2))) != 0);
%o A270532 (PARI) isok(n) = my(p=prime(n), m=p*(p+1)/2); prod(k=1, p, Mod(fibonacci(k), m)); \\ _Michel Marcus_, May 14 2021
%Y A270532 Cf. A000057, A003266, A270475.
%K A270532 nonn
%O A270532 1,2
%A A270532 _Altug Alkan_, Mar 18 2016