A164334 Quartic recurrence sequence a(0) = 1, a(n) = n*a(n-1)^4.

1, 1, 2, 48, 21233664, 1016411962239204484414785454080

Offset

0,3

Comments

Number of different orderings for n-input trees in a Free Quaternary Decision Diagram.

The next term has 121 digits. - Harvey P. Dale, Dec 19 2016

Links

G. C. Greubel, Table of n, a(n) for n = 0..7

Formula

a(0) = 1, a(n) = n*a(n-1)^4.

Mathematica

nxt[{n_, a_}]:={n+1, (n+1)a^4}; NestList[nxt, {0, 1}, 5][[All, 2]] (* Harvey P. Dale, Dec 19 2016 *)

Prog

(PARI) a(n) = if (n==0, 1, n*a(n-1)^4); \\ Michel Marcus, Sep 14 2017

Crossrefs

Quartic extension of A052129 and A123851.

Sequence in context: A152688 A046873 A261125 * A100540 A007861 A296142

Adjacent sequences: A164331 A164332 A164333 * A164335 A164336 A164337

Keyword

nonn

Author

David Willingham (D.Willingham(AT)wmin.ac.uk), Aug 13 2009

Status

approved