A086814 a(n) = ceiling( (1 + n + 2*n^2 + 4*n^3)/(1 + 2*n + n^2) ).

2, 5, 9, 12, 16, 20, 24, 27, 31, 35, 39, 43, 47, 51, 55, 59, 63, 67, 71, 75, 79, 83, 87, 91, 95, 99, 103, 107, 111, 115, 119, 123, 127, 131, 135, 139, 143, 147, 151, 155, 159, 163, 167, 171, 175, 179, 183, 187, 191, 195

Offset: 1

Author

Wang Dan (wangdan01(AT)lycos.com), Aug 06 2003

Keywords

• nonn
• easy

Examples

			a(2) = ceiling( (1*2^0 + 1*2^1 + 2*2^2 + 4*2^3)/(1*2^0 + 2*2^1 + 1*2^2) ) = ceiling(43/9) = ceiling(4.7777...) = 5.
		

Crossrefs

Cf. A086790.

Programs

Mathematica

Table[Ceiling[(1+n+2n^2+4n^3)/(1+2n+n^2)],{n,50}] (* Harvey P. Dale, Aug 11 2019 *)

PARI

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