A083478 a(n) is the smallest k > 0 such that k*Palindrome(n)+1 is a palindrome.
1, 1, 1, 1, 1, 1, 1, 1, 6, 10, 5, 7, 8, 2, 9, 3, 4, 6, 100, 10, 5, 4, 3, 2, 2, 2, 2, 2, 50, 50, 5, 4, 3, 2, 2, 2, 2, 2, 40, 40, 40, 7, 797, 2, 2, 2, 2, 2, 25, 30, 25, 420, 8, 2, 2, 2, 2, 2, 20, 20, 20, 20, 20, 2, 32, 117, 24, 28, 20, 20, 20, 20, 20, 89, 9, 52, 1870, 150, 20, 20, 20, 20, 20, 85
Offset: 1
Examples
a(11) = 5 because A002113(11) = 22 and 111 = 5*22+1.
Links
- Harvey P. Dale, Table of n, a(n) for n = 1..130
Crossrefs
Cf. A083477.
Programs
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Mathematica
skpal[n_]:=Module[{k=1},While[!PalindromeQ[k*n+1],k++];k]; skpal/@Select[ Range[ 1000],PalindromeQ] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Jul 22 2018 *)
Formula
Extensions
Corrected and extended by David Wasserman, Nov 16 2004