A306785 Primes p such that p^2 divides A050443(p).

2, 5, 1051

Offset

1,1

Comments

A050443(p) is divisible by p for p prime, so sequence looks for primes p such that p^2 divides A050443(p).

No more terms < 10^11. - Lucas A. Brown, Jan 27 2021

Links

Table of n, a(n) for n=1..3.

Example

A050443(2) = 0 is divisible by 2^2.
A050443(5) = 0 is divisible by 5^2.
A050443(1051) is divisible by 1051^2.

Prog

(PARI) M = [0, 1, 0, 0; 0, 0, 1, 0; 0, 0, 0, 1; 1, 1, 0, 0];
b(n) = lift( ( Mod(M, n^2)^n * [4, 0, 0, 3]~)[1] ); \\ A050443(n) mod n^2
forprime(n=2, 10^10, if( b(n)==0, print1(n, ", ") ) ); \\ Joerg Arndt, Mar 11 2019

Crossrefs

Cf. A000040, A050443, A173656, A306786.

Sequence in context: A369022 A078748 A051131 * A119748 A101341 A079014

Adjacent sequences: A306782 A306783 A306784 * A306786 A306787 A306788

Keyword

nonn,more,bref

Author

Seiichi Manyama, Mar 09 2019

Status

approved