VOOZH about

URL: https://oeis.org/A379964

⇱ A379964 - OEIS

login
A379964
a(n) = 1 if (n^2)-1 is not divisible by p^p for any prime p, otherwise 0.
2
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.
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.
Sequence in context: A361123 A125122 A379959 * A101455 A000035 A188510
KEYWORD
nonn
AUTHOR
Antti Karttunen, Jan 24 2025
STATUS
approved