A263084 a(n) = A263086(n) - A263085(n).

1, 2, 4, 6, 7, 11, 13, 14, 18, 22, 22, 28, 29, 31, 37, 41, 41, 46, 48, 52, 58, 62, 60, 68, 71, 73, 79, 83, 83, 93, 95, 96, 100, 104, 108, 118, 120, 120, 124, 132, 131, 141, 141, 145, 155, 157, 157, 165, 169, 172, 178, 184, 180, 190, 196, 202, 208, 210, 208, 220, 221, 223, 231, 237, 241, 251, 251, 251, 257, 267, 267, 278

Offset: 1

Author

Antti Karttunen, Oct 12 2015

Keywords

• nonn

Comments

See also the Plot2-link at A263086.

Links

• Antti Karttunen, Table of n, a(n) for n = 1..10082

Crossrefs

Cf. A000005, A001620, A099774, A099777, A263085, A263086.

Cf. also A262518, A262519.

Programs

Mathematica

Accumulate[Table[Subtract @@ DivisorSigma[0, 2*n - {0, 1}], {n, 1, 100}]] (* Amiram Eldar, Jan 25 2025 *)

PARI

list(lim) = {my(s = 0); for(n = 1, lim, s += numdiv(2*n) - numdiv(2*n-1); print1(s, ", "));} \\ Amiram Eldar, Jan 25 2025

Scheme

(define (A263084 n) (- (A263086 n) (A263085 n)))

Formula

a(n) = A263086(n) - A263085(n).

a(n) ~ n * (log(n) + 2*gamma - log(2) - 1), where gamma is Euler's constant (A001620). - Amiram Eldar, Jan 25 2025