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A260262 Number of digits of hyperfactorial(hyperfactorial(n)). 2
1, 1, 5, 10703, 1614696745, 28812381422477890, 100652205682053466439353073, 100862590668529143951825397261798321446, 39596172587764149886638486692811308322476202830248047, 7942534398808419809836601901425429825855063583537701822391757140131840 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

Matthew Campbell, Table of n, a(n) for n = 0..27

FORMULA

a(n) = floor(log_10(hyperfactorial(hyperfactorial(n))))+1.

a(n) = A055642(A002109(A002109(n))).

EXAMPLE

Hyperfactorial(Hyperfactorial(1)) = 1.  There is 1 digit in the number 1.  Because of this, a(1) = 1.

MATHEMATICA

Table[Floor[Log[10, Hyperfactorial[Hyperfactorial[n]]]] + 1, {n, 0, 3}]

PROG

(PARI) hyperfactorial(n)=prod(k=2, n, k^k)

first(m)=vector(m, i, #digits(hyperfactorial(hyperfactorial(i)))) \\ Anders Hellström, Aug 29 2015

CROSSREFS

Cf. A002109, A055642.

Sequence in context: A160741 A101846 A292742 * A058051 A242772 A089989

Adjacent sequences:  A260259 A260260 A260261 * A260263 A260264 A260265

KEYWORD

nonn,easy,base

AUTHOR

Matthew Campbell, Jul 21 2015

STATUS

approved

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Last modified October 19 03:15 EDT 2019. Contains 328211 sequences. (Running on oeis4.)