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 A135549 Number of bases b, 1 < b < n-1, in which n is a palindrome. 5
 0, 0, 0, 0, 0, 1, 0, 1, 1, 1, 2, 0, 1, 1, 1, 2, 2, 2, 2, 0, 2, 3, 1, 1, 3, 1, 3, 2, 3, 1, 2, 2, 2, 2, 2, 1, 4, 1, 2, 1, 4, 1, 3, 1, 2, 3, 3, 0, 4, 1, 3, 3, 4, 0, 3, 3, 3, 3, 1, 1, 5, 1, 2, 4, 3, 4, 3, 2, 3, 1, 3, 1, 5, 2, 2, 2, 2, 1, 5, 0, 6, 2, 3, 1, 5, 4, 2, 1, 4, 1, 4, 3, 4, 3, 1, 1, 5, 1, 4, 3, 6, 1, 3, 0, 5 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,11 COMMENTS Every integer n is a palindrome when expressed in unary, or in base n-1 (where is will be 11). So here we assume 1 < b < n-1. LINKS T. D. Noe, Table of n, a(n) for n=0..10000 John P. Linderman, Description of A135549-A135551 and A016038 John P. Linderman, Perl program [Use the command: palin.pl] FORMULA a(n) = A065531(n)-1 = A126071(n)-2 for n>2. - T. D. Noe, Feb 28 2008 MATHEMATICA a = {0, 0, 0}; For[n = 4, n < 100, n++, c = 0; For[b = 2, b < n - 1, b++, If[IntegerDigits[n, b] == Reverse[IntegerDigits[n, b]], c++ ]]; AppendTo[a, c]]; a - Stefan Steinerberger, Feb 27 2008 Table[cnt=0; Do[d=IntegerDigits[n, b]; If[d==Reverse[d], cnt++ ], {b, 2, n-2}]; cnt, {n, 0, 100}] - T. D. Noe, Feb 28 2008 CROSSREFS Cf. A135550, A135551, A016038. Cf. A016038 (non-palindromic numbers in any base 1 < b < n-1) Sequence in context: A051160 A051159 A035697 * A124737 A121303 A166396 Adjacent sequences:  A135546 A135547 A135548 * A135550 A135551 A135552 KEYWORD nonn,base AUTHOR John P. Linderman (jpl(AT)research.att.com), Feb 26 2008, Feb 28 2008 STATUS approved

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