A373137 a(n) = 1 if A276085(n) is a multiple of 8, otherwise 0, where A276085 is the primorial base log-function.

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

Offset

1

Links

Antti Karttunen, Table of n, a(n) for n = 1..100000

Index entries for characteristic functions

Index entries for sequences computed from indices in prime factorization

Index entries for sequences related to primorial numbers

Formula

a(n) = [A276085(n) == 0 (mod 8)], where [ ] is the Iverson bracket.

a(n) <= A369001(n).

Prog

(PARI)
A002110(n) = prod(i=1, n, prime(i));
A276085(n) = { my(f = factor(n)); sum(k=1, #f~, f[k, 2]*A002110(primepi(f[k, 1])-1)); };
A373137(n) = !(A276085(n)%8);

Crossrefs

Characteristic function of A373138.

Cf. A002110, A276085.

Cf. also A369001.

Sequence in context: A373258 A359465 A353675 * A015868 A323402 A240355

Adjacent sequences: A373134 A373135 A373136 * A373138 A373139 A373140

Keyword

nonn

Author

Antti Karttunen, May 26 2024

Status

approved