A379964 a(n) = 1 if (n^2)-1 is not divisible by p^p for any prime p, otherwise 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, 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, 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, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1

Offset

1

Comments

a(n) = 1 if (n^2)-1 is in A048103, otherwise 0.

Links

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

Index entries for characteristic functions.

Formula

a(n) = A359550((n^2)-1).

a(n) >= A379971(n).

Prog

(PARI)
A359550(n) = { my(pp); forprime(p=2, , pp = p^p; if(!(n%pp), return(0)); if(pp > n, return(1))); };
A379964(n) = A359550((n^2)-1);

Crossrefs

Characteristic function of A379965.

Cf. A048103, A359550, A379971.

Sequence in context: A361123 A125122 A379959 * A101455 A000035 A188510

Adjacent sequences: A379961 A379962 A379963 * A379965 A379966 A379967

Keyword

nonn,new

Author

Antti Karttunen, Jan 24 2025

Status

approved