A049854 a(n)=Sum{a(k): k=0,1,2,...,n-3,n-1}; a(n-2) is not a summand; 2 initial terms required.

1, 3, 3, 4, 8, 15, 26, 45, 79, 139, 244, 428, 751, 1318, 2313, 4059, 7123, 12500, 21936, 38495, 67554, 118549, 208039, 365083, 640676, 1124308, 1973023, 3462414, 6076113, 10662835, 18711971, 32837220, 57625304, 101125359

Offset

0,2

Links

Table of n, a(n) for n=0..33.

Index entries for linear recurrences with constant coefficients, signature (2, -1, 1).

Formula

a(n)=2*a(n-1)-a(n-2)+a(n-3); 3 initial terms required.

Mathematica

LinearRecurrence[{2, -1, 1}, {1, 3, 3}, 40] (* Harvey P. Dale, Jun 08 2022 *)

Crossrefs

Sequence in context: A160646 A019466 A111573 * A353265 A366758 A291872

Adjacent sequences: A049851 A049852 A049853 * A049855 A049856 A049857

Keyword

nonn

Author

Clark Kimberling

Status

approved