A147677 Subtract 5, add 8, repeat.

7, 2, 10, 5, 13, 8, 16, 11, 19, 14, 22, 17, 25, 20, 28, 23, 31, 26, 34, 29, 37, 32, 40, 35, 43, 38, 46, 41, 49, 44, 52, 47, 55, 50, 58, 53, 61, 56, 64, 59, 67, 62, 70, 65, 73, 68, 76, 71, 79, 74, 82, 77, 85, 80, 88, 83, 91, 86, 94, 89, 97, 92, 100, 95, 103, 98, 106, 101, 109

Offset: 1

Author

N. J. A. Sloane, Apr 21 2009

Keywords

• nonn
• easy

Comments

A147675-A147678 are from a quiz that someone asked me to help them with.

Links

• Index entries for linear recurrences with constant coefficients, signature (1,1,-1).

Programs

Mathematica

LinearRecurrence[{1,1,-1},{7,2,10},80] (* Harvey P. Dale, Jan 16 2015 *)

Formula

From Zak Seidov, Apr 22 2009: (Start)

a(n) = a(n-2) + 3.

a(n) = (1/4)*(6*n + 9 - 13*(-1)^n). (End)

From R. J. Mathar, Apr 22 2009: (Start)

a(n) = a(n-1) + a(n-2) - a(n-3) = 3*n/2 + 9/4 + 13*(-1)^(n+1)/4.

G.f.: x*(7-5*x+x^2)/((1+x)*(x-1)^2). (End)

Extensions

More terms from Zak Seidov and R. J. Mathar, Apr 22 2009