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A109214 Product of a(n-1) and digit reversal of a(n-2). 2
1, 2, 2, 4, 8, 32, 256, 5888, 3838976, 34109301760, 231888097227054080, 1556059601911449331359933440, 125186119679477750610733678211850458005934080, 55507466796083630515105997822341552764197877620395801846452095434158080 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Cf. A000301 a(n) = a(n-1)*a(n-2), A004086 R(n) = digit reversal of n, A109213 a(n) = a(n-2)*R(a(n-1)).

The next term (a(15)) has 115 digits. [From Harvey P. Dale, Nov 14 2011]

LINKS

Table of n, a(n) for n=1..14.

FORMULA

a(n)=a(n-1)*R(a(n-2)).

MATHEMATICA

a[1]=1; a[2]=2; a[n_]:=a[n]=a[n-1]*FromDigits[Reverse[IntegerDigits[a[n-2]]]]; A109214=Table[a[n], {n, 13}]

Transpose[NestList[{Last[#], Last[#]FromDigits[Reverse[ IntegerDigits[ First[ #]]]]}&, {1, 2}, 13]][[1]] (* Harvey P. Dale, Nov 14 2011 *)

CROSSREFS

Cf. A000301, A004086, A109213.

Sequence in context: A100799 A070323 A109213 * A000301 A124439 A082836

Adjacent sequences:  A109211 A109212 A109213 * A109215 A109216 A109217

KEYWORD

base,nonn

AUTHOR

Zak Seidov, Jun 22 2005

EXTENSIONS

One more term (a(14)) from Harvey P. Dale, Nov 14 2011

STATUS

approved

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Last modified April 10 11:15 EDT 2021. Contains 342845 sequences. (Running on oeis4.)