A187891 a(0)=0, a(1)=5, a(n)=a(n-1)+a(n-2)-1.

0, 5, 4, 8, 11, 18, 28, 45, 72, 116, 187, 302, 488, 789, 1276, 2064, 3339, 5402, 8740, 14141, 22880, 37020, 59899, 96918, 156816, 253733, 410548, 664280, 1074827, 1739106, 2813932, 4553037, 7366968, 11920004, 19286971, 31206974, 50493944, 81700917

Offset: 0

Author

Vladimir Joseph Stephan Orlovsky, Mar 15 2011

Keywords

• nonn
• easy

Links

• Harvey P. Dale, Table of n, a(n) for n = 0..1000
• Index entries for linear recurrences with constant coefficients, signature (2,0,-1).

Crossrefs

Cf. A000071, A001611, A001612, A022120, A187890.

Programs

Mathematica

Join[{a=0,b=5},Table[c=a+b-1;a=b;b=c,{n,100}]]
nxt[{a_,b_}]:={b,a+b-1}; NestList[nxt,{0,5},40][[All,1]] (* Harvey P. Dale, Nov 03 2022 *)

Formula

a(n) = 1+A022120(n-2), n>2. - R. J. Mathar, Mar 15 2011

G.f.: -x^2*(-5+6*x) / ( (x-1)*(x^2+x-1) ). - R. J. Mathar, Mar 15 2011