A068665 - OEIS

%I #13 Oct 25 2019 20:12:16

%S 3,6,66,858,6006,66066,858858,222444222,444888444,21354645312,

%T 21375999957312,211643775577346112,211432343445544343234112,

%U 21354666687999978666645312,211432554877887788778455234112,211221333755564778877465557333122112

%N a(1) = 3; a(n) = smallest palindromic multiple of a(n-1).

%H Giovanni Resta, <a href="/A068665/b068665.txt">Table of n, a(n) for n = 1..19</a>

%t a[1] = 3; 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, 16}]

%t nxt[n_]:=Module[{k=2},While[k*n!=IntegerReverse[k*n],k++];k*n]; NestList[ nxt,3,15] (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, Sep 14 2016 *)

%Y Cf. A068664, A068666, A068667, A068668, A070069, A068971, A068972, A068973, A068974, A083149.

%K nonn,base

%O 1,1

%A _Amarnath Murthy_, Mar 01 2002

%E More terms from _David W. Wilson_; edited by _Patrick De Geest_, Mar 30 2002

%E a(16) from _Giovanni Resta_, Sep 22 2019