A100799 - OEIS

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A100799

a(1) = 1, a(2) = 2, a(n) = product of nonzero digits of previous two terms.

1, 2, 2, 4, 8, 32, 48, 192, 576, 3780, 35280, 40320, 5760, 5040, 4200, 160, 48, 192, 576, 3780, 35280, 40320, 5760, 5040, 4200, 160, 48, 192, 576, 3780, 35280, 40320, 5760, 5040, 4200, 160, 48, 192, 576, 3780, 35280, 40320, 5760, 5040, 4200, 160, 48

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OFFSET

1,2

COMMENTS

Pattern of ten terms repeats beginning with a(7)=48.

LINKS

Table of n, a(n) for n=1..47.

MATHEMATICA

nxt[{a_, b_}]:={b, Times@@Select[Flatten[IntegerDigits/@{a, b}], #>0&]}; NestList[nxt, {1, 2}, 50][[;; , 1]] (* or *) PadRight[{1, 2, 2, 4, 8, 32}, 50, {35280, 40320, 5760, 5040, 4200, 160, 48, 192, 576, 3780}] (* Harvey P. Dale, Jun 10 2023 *)

CROSSREFS

Sequence in context: A032439 A096096 A300759 * A070323 A109213 A109214

Adjacent sequences: A100796 A100797 A100798 * A100800 A100801 A100802

KEYWORD

base,easy,nonn

AUTHOR

Amarnath Murthy, Dec 17 2004

EXTENSIONS

Corrected and extended by Ray Chandler, Dec 19 2004

STATUS

approved