A108082 Sum_{i=0..n} binomial(2n+i,2i).

1, 4, 26, 176, 1204, 8273, 56967, 392688, 2708322, 18683233, 128892764, 889172365, 6133354976, 42300883471, 291696384929, 2011120962840, 13863370486596, 95548230542403, 658416136868846, 4536321401562529

Offset

0,2

Links

Table of n, a(n) for n=0..19.

Formula

a(n) ~ phi^(4*n + 1) / sqrt(5), where phi = A001622 = (1 + sqrt(5))/2 is the golden ratio. - Vaclav Kotesovec, Apr 12 2018

Mathematica

Table[Sum[Binomial[2n+i, 2i], {i, 0, n}], {n, 0, 20}] (* Harvey P. Dale, Apr 12 2018 *)

Crossrefs

Sequence in context: A220305 A210911 A278416 * A199490 A116429 A084134

Adjacent sequences: A108079 A108080 A108081 * A108083 A108084 A108085

Keyword

nonn

Author

Ralf Stephan, Jun 03 2005

Status

approved