A356172 - OEIS

A356172

a(n) = 1 if n is odd and not divisible by two consecutive prime numbers, otherwise 0.

1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 0, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 0, 0, 1, 0, 1, 0, 1, 0, 1, 0, 0, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 0, 0, 0, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 0, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1

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OFFSET

COMMENTS

a(n) = 1 if n is odd and relatively prime to A003961(n), otherwise 0.

a(n) = 1 if n and the smallest positive k such that n divides k*A003961(k) are coprime, otherwise 0.

LINKS

Antti Karttunen, Table of n, a(n) for n = 1..65537

Index entries for characteristic functions

Index entries for sequences computed from indices in prime factorization

FORMULA

a(n) = A000035(n) * A356173(n).

a(n) = [gcd(n, A356164(n)) == 1], where [ ] is the Iverson bracket.