A000277 3*n - 2*floor(sqrt(4*n+5)) + 5.

1, 2, 5, 6, 9, 10, 13, 16, 17, 20, 23, 24, 27, 30, 33, 34, 37, 40, 43, 44, 47, 50, 53, 56, 57, 60, 63, 66, 69, 70, 73, 76, 79, 82, 85, 86, 89, 92, 95, 98, 101, 102, 105, 108, 111, 114, 117, 120, 121, 124, 127, 130, 133, 136, 139, 140, 143, 146, 149, 152, 155

Offset

0,2

Links

T. D. Noe, Table of n, a(n) for n = 0..1000

Mathematica

Table[3*n - 2*Floor[Sqrt[4 n + 5]] + 5, {n, 0, 100}] (* T. D. Noe, Jun 19 2012 *)

Prog

(PARI) a(n)=3*n-2*sqrtint(4*n+5)+5

Crossrefs

Sequence in context: A276883 A288552 A187583 * A003664 A065890 A162177

Adjacent sequences: A000274 A000275 A000276 * A000278 A000279 A000280

Keyword

nonn,easy

Author

N. J. A. Sloane, based on a message from Michael S. Cann Jr. (mscannjr(AT)gmail.com)

Status

approved