A217473 Product of the first n+1 odd-indexed Lucas numbers A000032.

1, 4, 44, 1276, 96976, 19298224, 10054374704, 13714167096256, 48973290700730176, 457851294761126415424, 11206368290573330143917824, 718092873691648422292110244096, 120467978583384630972146706659789056

Offset

0,2

Comments

This sequence is used in A217472 to produce the integer instead of rational Ozeki-Prodinger triangle, and the corresponding sequence A217474.

Links

Table of n, a(n) for n=0..12.

Formula

a(n) = Product_{i=0..n} L(2*i+1), n >= 0, with the Lucas numbers L=A000032.

a(n) ~ c * phi^(n*(n+2)), where c = Product_{k>=1} (1 - 1/phi^(4*k+2)) = 0.93529381211738925891... . - Amiram Eldar, Jul 09 2025

Mathematica

FoldList[Times, LucasL[Range[1, 26, 2]]] (* Amiram Eldar, Jul 09 2025 *)

Crossrefs

Cf. A000032, A001622 (phi), 2*A070825 (product of the first n+1 Lucas numbers).

Cf. A217472, A217474.

Sequence in context: A155556 A188456 A306372 * A127635 A134174 A391487

Adjacent sequences: A217470 A217471 A217472 * A217474 A217475 A217476

Keyword

nonn,easy

Author

Wolfdieter Lang, Oct 12 2012

Status

approved