This site is supported by donations to The OEIS Foundation.

 Annual Appeal: Please make a donation to keep the OEIS running. In 2018 we replaced the server with a faster one, added 20000 new sequences, and reached 7000 citations (often saying "discovered thanks to the OEIS"). Other ways to donate

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A068665 a(1) = 3; a(n) = smallest palindromic multiple of a(n-1). 9
 3, 6, 66, 858, 6006, 66066, 858858, 222444222, 444888444, 21354645312, 21375999957312, 211643775577346112, 211432343445544343234112, 21354666687999978666645312, 211432554877887788778455234112 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS MATHEMATICA 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}] 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 *) CROSSREFS Cf. A068664, A068666, A068667, A068668, A070069, A068971, A068972, A068973, A068974. Sequence in context: A225789 A076551 A127637 * A229236 A050722 A069502 Adjacent sequences:  A068662 A068663 A068664 * A068666 A068667 A068668 KEYWORD base,nonn AUTHOR Amarnath Murthy, Mar 01 2002. EXTENSIONS More terms from David W. Wilson; edited by Patrick De Geest, Mar 30 2002. STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified December 16 17:59 EST 2018. Contains 318187 sequences. (Running on oeis4.)