A063038 a(n) = floor(n*sqrt(n)) - d(n), where d(n) is the number of divisors function.

0, 0, 3, 5, 9, 10, 16, 18, 24, 27, 34, 35, 44, 48, 54, 59, 68, 70, 80, 83, 92, 99, 108, 109, 122, 128, 136, 142, 154, 156, 170, 175, 185, 194, 203, 207, 223, 230, 239, 244, 260, 264, 279, 285, 295, 307, 320, 322, 340, 347, 360, 368, 383, 388, 403, 411, 426, 437

Offset

1,3

Links

Table of n, a(n) for n=1..58.

Formula

a(n) = A000093(n) - A000005(n). - Michel Marcus, Apr 13 2024

Mathematica

Table[Floor[n*Sqrt[n]] - DivisorSigma[0, n], {n, 50}] (* Wesley Ivan Hurt, Jun 09 2014 *)

Prog

(PARI) j=[]; for(n=1, 100, j=concat(j, floor(n*sqrt(n))-numdiv(n))); j

Crossrefs

Cf. A000005, A000093, A055682.

Sequence in context: A286065 A316296 A344293 * A236309 A304588 A335058

Adjacent sequences: A063035 A063036 A063037 * A063039 A063040 A063041

Keyword

easy,nonn

Author

Jason Earls, Aug 03 2001

Status

approved