A255875 a(n) = Fibonacci(n+2) + n - 2.

1, 3, 6, 10, 16, 25, 39, 61, 96, 152, 242, 387, 621, 999, 1610, 2598, 4196, 6781, 10963, 17729, 28676, 46388, 75046, 121415, 196441, 317835, 514254, 832066, 1346296, 2178337, 3524607, 5702917, 9227496, 14930384, 24157850, 39088203, 63246021, 102334191, 165580178, 267914334

Offset: 1

Author

Geoff Ahiakwo, Mar 08 2015

Keywords

• nonn
• easy

Links

• Andrew Howroyd, Table of n, a(n) for n = 1..1000
• Index entries for linear recurrences with constant coefficients, signature (3,-2,-1,1).

Programs

Mathematica

Array[Fibonacci[# + 2] + # - 2 &, 30] (* Michael De Vlieger, Jul 10 2015 *)

PARI

main(size)={return( vector(size,n,fibonacci(n+2)+n-2));} /* Anders Hellström, Jul 11 2015 */

Formula

G.f.: x*(-1+x^2+x^3) / ( (x^2+x-1)*(x-1)^2 ). - R. J. Mathar, Jul 10 2015

a(n) = A232896(n+1)-2. - R. J. Mathar, Jul 10 2015

Extensions

Terms a(31) and beyond from Andrew Howroyd, Dec 23 2019