A353473 a(n) = 1 if n is a number of the form p * q^2, where p and q are primes with p < q, otherwise 0.

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

Offset

1

Comments

a(n) = 1 if n is not a cube of prime and A032742(n) is a square of prime, otherwise 0.

Links

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

Index entries for characteristic functions

Formula

a(n) = A143731(n) * A302048(A032742(n)).

a(n) = A353472(n) - A353474(n).

Prog

(PARI)
A032742(n) = if(1==n, n, n/vecmin(factor(n)[, 1]));
A353473(n) = (!isprimepower(n) && 2==isprimepower(A032742(n)));

Crossrefs

Characteristic function of A095990.

Cf. A010055, A032742, A143731, A302048, A353472, A353474.

Sequence in context: A181837 A185709 A011732 * A378661 A011731 A085980

Adjacent sequences: A353470 A353471 A353472 * A353474 A353475 A353476

Keyword

nonn

Author

Antti Karttunen, Apr 21 2022

Status

approved