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A068664 a(1) = 1, a(n) = smallest palindromic multiple of a(n-1). 10
1, 2, 4, 8, 88, 616, 6776, 88088, 616616, 232464232, 21154245112, 232696696232, 21175399357112, 21154245133154245112, 232696696464696696232, 21175399378287399357112, 63386501441764911946714410568336 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..17.

MATHEMATICA

a=1; Print[a]; For[n = 2, n <= 15, n++, {an = a; k = 2; str = ToString[k*an]; rstr = StringReverse[str]; While[str != rstr, {k = k + 1; str = ToString[k*an]; rstr = StringReverse[str]; If[k*an > 10^20, {Print["Too big"]; Abort[]}]}]; a := k*an; Print[k, " ", a]; }]

spm[n_]:=Module[{k=2}, While[!PalindromeQ[k*n], k++]; k*n]; NestList[spm, 1, 15] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, May 02 2019 *)

CROSSREFS

A068667 (from a(3) on) and this sequence (from a(6) on) coincide.

Cf. A068665, A068666, A068667, A068668, A070069, A068971, A068972, A068973, A068974.

Sequence in context: A076886 A309565 A046385 * A199166 A018605 A058262

Adjacent sequences:  A068661 A068662 A068663 * A068665 A068666 A068667

KEYWORD

base,nonn

AUTHOR

Amarnath Murthy, Mar 01 2002.

EXTENSIONS

Extended and edited by John W. Layman, Mar 18 2002. Last two terms from David W. Wilson and Patrick De Geest, Mar 30 2002.

STATUS

approved

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Last modified October 22 00:52 EDT 2019. Contains 328315 sequences. (Running on oeis4.)