A070069 a(1) = 11; a(n) = smallest palindromic multiple of a(n-1).

11, 22, 44, 88, 616, 6776, 88088, 616616, 232464232, 21154245112, 232696696232, 21175399357112, 21154245133154245112, 232696696464696696232, 21175399378287399357112, 63386501441764911946714410568336

Offset

1,1

Links

Table of n, a(n) for n=1..16.

Mathematica

e[1] = 11; e[n_] := e[n] = Block[{k = 2}, While[k*e[n - 1] != ToExpression[ StringReverse[ ToString[k*e[n - 1]]]], k++ ]; k*e[n - 1]]; Table[e[n], {n, 1, 12}]
spm[a_]:=Module[{k=2}, While[!PalindromeQ[k*a], k++]; k*a]; NestList[spm, 11, 15] (* Harvey P. Dale, Mar 20 2026 *)

Crossrefs

Cf. A068664 (from a(5) on) and this sequence (from a(4) on) coincide.

Cf. A068664, A068665, A068666, A068667, A068668, A068971, A068972, A068973, A068974.

Sequence in context: A242958 A367348 A005015 * A178664 A292926 A109687

Adjacent sequences: A070066 A070067 A070068 * A070070 A070071 A070072

Keyword

base,nonn

Author

Robert G. Wilson v, Apr 19 2002

Status

approved