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A171881 Square array, read by antidiagonals, where T(n,k)=n^^k for n>=0, k>=1. 1
0, 1, 1, 2, 1, 1, 3, 4, 1, 1, 4, 27, 16, 1, 1, 5, 256, 19683, 256, 1, 1, 6, 3125, 4294967296, 7625597484987, 65536, 1, 1, 7, 46656, 298023223876953125, 340282366920938463463374607431768211456 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

0,4

COMMENTS

n^^k is defined the left-associative way: n^^2=n^n, n^^3=(n^n)^n=n^(n^2), n^^4=((n^n)^n)^n=n^(n^3), and in general n^^k=n^(n^(k-1)).

More terms on Munafo website.

Array begins:

0,1,1,1,1,1,...

1,1,1,1,1,1,...

2,4,16,256,65536,...

3,27,19683,...

4,256,4294967296,...

5,3125,...

6,46656,...

LINKS

Table of n, a(n) for n=0..31.

R. Munafo, Hyper4 Iterated Exponential Function

CROSSREFS

Cf. A171882.

Sequence in context: A104495 A093541 A336187 * A321877 A320251 A210341

Adjacent sequences:  A171878 A171879 A171880 * A171882 A171883 A171884

KEYWORD

nonn,tabl

AUTHOR

Robert Munafo, Jan 21 2010

STATUS

approved

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Last modified November 30 05:31 EST 2020. Contains 338781 sequences. (Running on oeis4.)