1,3

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

a(1) = 0; for n > 1, a(n) = A302777(n) + a(n-1).

For all n >= 1, a(A050376(n)) = n.

(PARI)

A209229(n) = (n && !bitand(n, n-1));

A302777(n) = A209229(isprimepower(n));

s=0; for(n=1, 105, s+=A302777(n); print1(s, ", "));

Partial sums of A302777. A left inverse of A050376.

Cf. A302785, A302786.

Differs from A203967 for the first time at n=64, where a(64) = 23, while A203967(64) = 24.

Cf. also A000720, A025528.

Sequence in context: A047741 A047784 A047742 * A203967 A267530 A050292

Adjacent sequences: A302775 A302776 A302777 * A302779 A302780 A302781

nonn

Antti Karttunen, Apr 16 2018

approved