A005832 Product k^(2^(k-1)), k = 1..n. (Formerly M3724)

1, 4, 324, 21233664, 3240000000000000000, 25786061996226338865429872640000000000000000

Offset

1,2

References

M. E. Mays, A worst case of the Fibonacci-Sylvester expansion, J. Combin. Math. Combin. Computing, 1 (1987), 141-148.

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Links

Alois P. Heinz, Table of n, a(n) for n = 1..10

Maple

a:= proc(n) a(n):= `if`(n=1, 1, a(n-1)*n^(2^(n-1))) end:
seq(a(n), n=1..7);  # Alois P. Heinz, May 25 2013

Mathematica

Table[Product[k^(2^(k - 1)), {k, 1, n}], {n, 1, 10}] (* Soumadeep Ghosh, Feb 15 2016 *)

Prog

(PARI) a(n) = prod(k=1, n, k^(2^(k-1))) \\ Michel Marcus, May 25 2013

Crossrefs

Sequence in context: A368619 A368369 A053917 * A195501 A075768 A378720

Adjacent sequences: A005829 A005830 A005831 * A005833 A005834 A005835

Keyword

nonn,easy

Author

N. J. A. Sloane, Jeffrey Shallit

Status

approved