A283260 Product of the products of elements of all the nonempty subsets of the sets of numbers from 1 to n.

1, 4, 1296, 110075314176, 1848842588950364160000000000000000, 27204445973673520186989292010512474445356561349778469394841600000000000000000000000000000000

Offset

1,2

Comments

a(7) has 237 digits.

Links

N. J. A. Sloane, Table of n, a(n) for n = 1..8

Formula

a(n) = (n!)^(2^(n-1)).

Example

Rows with nonempty subsets of the sets of numbers from 1 to n:
{1};
{1}, {2}, {1, 2};
{1}, {2}, {3}, {1, 2}, {1, 3}, {2, 3}, {1, 2, 3};
...
Rows with the products of elements of these subsets:
1;
1, 2, 2;
1, 2, 3, 2, 3, 6, 6;
...
a(1) = (1), a(2) = (1*2*2) = 4, a(3) = (1*2*3*2*3*6*6) = 1296, ...

Prog

(PARI) a(n)=n!^2^(n-1) \\ Charles R Greathouse IV, Mar 06 2017

Crossrefs

Cf. A000225, A001788, A033312, A067174, A229338, A283261.

Sequence in context: A324299 A227850 A079711 * A217601 A172925 A167071

Adjacent sequences: A283257 A283258 A283259 * A283261 A283262 A283263

Keyword

nonn,easy

Author

Jaroslav Krizek, Mar 04 2017

Status

approved