A389913 a(n) = 1 if A048675(n) is in A186891\{1}, otherwise 0.

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

Offset

1

Links

Antti Karttunen, Table of n, a(n) for n = 1..56057

Index entries for characteristic functions.

Formula

a(n) = A283991(A048675(n)) = A389911(A260443(A048675(n))).

Prog

(PARI)
A048675(n) = { my(f = factor(n)); sum(k=1, #f~, f[k, 2]*2^primepi(f[k, 1]))/2; };
ps(n) = if(n<2, n, if(n%2, ps(n\2)+ps(n\2+1), 'x*ps(n\2)));
A283991(n) = polisirreducible(ps(n));
A389913(n) = A283991(A048675(n));

Crossrefs

Characteristic function of A389914.

Cf. A186891, A048675, A260443, A283991, A389911.

Sequence in context: A062301 A374769 A181712 * A380173 A288729 A335617

Adjacent sequences: A389910 A389911 A389912 * A389914 A389915 A389916

Keyword

nonn

Author

Antti Karttunen, Dec 03 2025

Status

approved