A068668 a(1) = 9; a(n) = smallest palindromic multiple of a(n-1).

9, 99, 1881, 171171, 1882881, 306909603, 11355655311, 1033364633301, 1034397997934301, 10241574577547514201, 10231343244544544234313201, 112544775689989986577445211, 1023144555797698967975554413201, 102221350448336861989168633844053122201, 11233003103852144358833233885344125830130033211

Offset: 1

Author

Amarnath Murthy, Mar 01 2002

Keywords

• base
• nonn

Crossrefs

Cf. A068664, A068665, A068666, A068667, A070069, A068971, A068972, A068973, A068974.

Programs

Mathematica

a[1] = 9; a[n_] := a[n] = Block[{k = 2}, While[k*a[n - 1] != ToExpression[ StringReverse[ ToString[k*a[n - 1]]]], k++ ]; k*a[n - 1]]; Table[a[n], {n, 1, 13}] (* Robert G. Wilson v, Apr 19 2002 *)

Extensions

More terms from Sascha Kurz, Mar 27 2002

Edited by N. J. A. Sloane, Apr 19 2007

a(14)-a(15) from Giovanni Resta, Sep 25 2019