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A245384 a(n) = (1 + a(n-1)) * a(n-2) * a(n-3) with a(1) = 1, a(2) = 2, a(3) = 3. 3
1, 2, 3, 8, 54, 1320, 570672, 40677571440, 30641887385179424640, 711307017047678652146384291462042880, 886599784992546696966754646294076268713472764725575212247451289600 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Michael Somos, Table of n, a(n) for n = 1..11

FORMULA

a(n) = A245366(n) - 1 for n>0.

a(n) = A245283(n+3) / A245283(n+2) for n>0.

MATHEMATICA

a[ n_] := If[ n < 4, Max[1, n], a[n] = (1 + a[n-1]) a[n-2] a[n-3]];

PROG

(PARI) {a(n) = if( n<4, max(1, n), (1 + a(n-1)) * a(n-2) * a(n-3))};

(MAGMA) I:=[1, 2, 3]; [n le 3 select I[n] else (1 + Self(n-1))*Self(n-2)* Self(n-3): n in [1..15]]; // G. C. Greubel, Aug 05 2018

CROSSREFS

Cf. A245283, A245366.

Sequence in context: A041979 A001686 A013205 * A292893 A042365 A160634

Adjacent sequences:  A245381 A245382 A245383 * A245385 A245386 A245387

KEYWORD

nonn

AUTHOR

Michael Somos, Aug 21 2014

STATUS

approved

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Last modified October 20 10:45 EDT 2019. Contains 328257 sequences. (Running on oeis4.)