A020967 a(n) = Sum_{k >=1} floor(n*sqrt(2)^(3-k)).

3, 9, 16, 22, 28, 36, 40, 49, 55, 62, 66, 76, 82, 87, 94, 103, 111, 116, 121, 130, 134, 141, 150, 157, 163, 170, 176, 182, 190, 196, 200, 212, 217, 227, 231, 238, 245, 250, 256, 266, 270, 277, 283, 291, 295, 307, 312, 320, 327, 333, 341, 347, 352, 360, 364

Offset

1,1

Links

G. C. Greubel, Table of n, a(n) for n = 1..1000

C. Kimberling, Problem 10520, Amer. Math. Mon. 103 (1996) p. 347.

Mathematica

Table[Sum[Floor[n*Sqrt[2]^(3-k)], {k, 1, 1000}] -1, {n, 1, 50}] (* G. C. Greubel, May 31 2018 *)

Prog

(PARI) j=[]; for(n=1, 100, j=concat(j, suminf(k=1, floor(n*sqrt(2)^(3-k) )))); j
(Magma) [(&+[Floor(n*Sqrt(2)^(3-k)): k in [1..1000]]): n in [1..30]]; // G. C. Greubel, May 31 2018

Crossrefs

Sequence in context: A214644 A184529 A338020 * A253547 A290371 A334563

Adjacent sequences: A020964 A020965 A020966 * A020968 A020969 A020970

Keyword

nonn

Author

Clark Kimberling

Extensions

More terms from Jason Earls, Jul 28 2001

Status

approved