A020966 a(n) = Sum_{k>=1} floor(n*sqrt(2)^(2-k)).

2, 6, 11, 15, 19, 25, 27, 34, 38, 43, 45, 53, 57, 60, 65, 72, 78, 81, 84, 91, 93, 98, 105, 110, 114, 119, 123, 127, 133, 137, 139, 149, 152, 160, 162, 167, 172, 175, 179, 187, 189, 194, 198, 204, 206, 216, 219, 225, 230, 234, 240, 244, 247, 253, 255, 262, 268, 273, 275, 281, 285, 288

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]^(2 - k)], {k, 1, 1000}], {n, 1, 50}] (* G. C. Greubel, May 31 2018 *)

Prog

(PARI) for(n=1, 30, print1(sum(k=1, 1000, floor(n*sqrt(2)^(2-k))), ", ")) \\ G. C. Greubel, May 31 2018
(Magma) [(&+[Floor(n*Sqrt(2)^(2-k)): k in [1..1000]]): n in [1..30]]; // G. C. Greubel, May 31 2018

Crossrefs

Sequence in context: A035487 A299637 A190889 * A193910 A215918 A078476

Adjacent sequences: A020963 A020964 A020965 * A020967 A020968 A020969

Keyword

nonn

Author

Clark Kimberling

Extensions

Terms a(31) onward added by G. C. Greubel, May 31 2018

Status

approved