A085899 - OEIS

A085899

a(n) = floor( 2*(1 + n + 2*n^2 + 4*n^3)/(1 + 2*n + n^2)).

4, 9, 16, 23, 30, 38, 46, 53, 61, 69, 77, 85, 93, 101, 109, 117, 124, 132, 140, 148, 156, 164, 172, 180, 188, 196, 204, 212, 220, 228, 236, 244, 252, 260, 268, 276, 284, 292, 300, 308, 316, 324, 332, 340, 348, 356, 364, 372, 380, 388

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OFFSET

1,1

LINKS

Table of n, a(n) for n=1..50.

EXAMPLE

a(2) = floor(2*(1*2^0+1*2^1+2*2^2+4*2^3)/(1*2^0+2*2^1+1*2^2)) = floor(2*43/9) = floor(9.55556) = 9.

MATHEMATICA

Table[Floor[(2(1+n+2n^2+4n^3))/(1+2n+n^2)], {n, 50}] (* Harvey P. Dale, Apr 01 2018 *)

PROG

(PARI) a(n) = floor(2*((1 + n + 2*n^2 + 4*n^3)/(1 + 2*n + n^2))); \\ Michel Marcus, Aug 31 2013

CROSSREFS

Cf. A086790, A086814, A086822.

Sequence in context: A162207 A092614 A313351 * A027874 A009850 A009853

Adjacent sequences: A085896 A085897 A085898 * A085900 A085901 A085902

KEYWORD

nonn,easy

AUTHOR

Wang Dan (wangdan01(AT)lycos.com), Aug 15 2003

EXTENSIONS

Definition corrected by Michel Marcus, Aug 31 2013

STATUS

approved