A171880 a(n) = a(n-1) + a(n-2)*a(n-3) + a(n-4)*a(n-5)^a(n-6); initial terms are 0, 0, 0, 1, 1, 1.

0, 0, 0, 1, 1, 1, 2, 4, 7, 16, 46, 166, 1014, 47066, 12348246366, 66716521529543607970475115226

Offset

0,7

Comments

First 6 terms are {0,0,0,1,1,1}; thereafter apply the recurrence. Note that 0^0=1.

Links

Table of n, a(n) for n=0..15.

Robert Munafo, Accelerating Sequences

Mathematica

nxt[{a_, b_, c_, d_, e_, f_}]:={b, c, d, e, f, f+e*d+c*Max[1, b]^Max[1, a]}; NestList[ nxt, {0, 0, 0, 1, 1, 1}, 14][[All, 1]] (* Harvey P. Dale, Jan 18 2019 *)

Crossrefs

Cf. A171879.

Sequence in context: A343869 A137568 A010355 * A171874 A113878 A293793

Adjacent sequences: A171877 A171878 A171879 * A171881 A171882 A171883

Keyword

nonn

Author

Robert Munafo, Jan 21 2010

Status

approved