A203480 a(n) = v(n+1)/v(n), where v = A203479.

4, 80, 6336, 1901824, 2167925760, 9505110118400, 162323441859870720, 10902076148767162433536, 2898720791385603198124032000, 3064112360434477703904869089280000, 12909951234577776926559241120412860416000

Offset

1,1

Links

G. C. Greubel, Table of n, a(n) for n = 1..55

Formula

a(n) = Product_{k=1..n} (2^k + 2^(n+1) - 2). - G. C. Greubel, Aug 28 2023

Mathematica

(* First program *)
f[j_]:= 2^j - 1; z = 15;
v[n_]:= Product[Product[f[k] + f[j], {j, k-1}], {k, 2, n}]
Table[v[n], {n, z}]               (* A203479 *)
Table[v[n+1]/v[n], {n, z-1}]      (* A203480 *)
Table[v[n+1]/(4*v[n]), {n, z-1}]  (* A203481 *)
(* Second program *)
Table[Product[2^(n+1) +2^k -2, {k, n}], {n, 20}] (* G. C. Greubel, Aug 28 2023 *)

Prog

(Magma) [(&*[2^j +2^(n+1) -2: j in [1..n]]): n in [1..20]]; // G. C. Greubel, Aug 28 2023
(SageMath) [product(2^j+2^(n+1)-2 for j in range(1, n+1)) for n in range(1, 21)] # G. C. Greubel, Aug 28 2023

Crossrefs

Cf. A093883, A203307, A203479.

Sequence in context: A012106 A156103 A204294 * A339854 A116189 A159063

Adjacent sequences: A203477 A203478 A203479 * A203481 A203482 A203483

Keyword

nonn

Author

Clark Kimberling, Jan 02 2012

Status

approved