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 A249155 Palindromic in bases 6 and 15. 7
 0, 1, 2, 3, 4, 5, 7, 14, 80, 160, 301, 602, 693, 994, 1295, 1627, 1777, 2365, 2666, 5296, 5776, 6256, 17360, 34720, 51301, 52201, 105092, 155493, 209284, 587846, 735644, 7904800, 11495701, 80005507, 80469907, 83165017, 89731777, 90196177 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 COMMENTS Intersection of A029953 and A029960. LINKS Ray Chandler and Chai Wah Wu, Table of n, a(n) for n = 1..71 (terms < 6^28). First 65 terms from Ray Chandler. Attila Bérczes and Volker Ziegler, On Simultaneous Palindromes, arXiv:1403.0787 [math.NT] EXAMPLE 301 is a term since 301 = 1221 base 6 and 301 = 151 base 15. MATHEMATICA palQ[n_Integer, base_Integer] := Block[{idn = IntegerDigits[n, base]}, idn == Reverse[idn]]; Select[Range[10^6] - 1, palQ[#, 6] && palQ[#, 15] &] PROG (Python) def palQ(n, b): # check if n is a palindrome in base b ....s = digits(n, b) ....return s == s[::-1] def palQgen(l, b): # generator of palindromes in base b of length <= 2*l ....if l > 0: ........yield 0 ........for x in range(1, l+1): ............for y in range(b**(x-1), b**x): ................s = digits(y, b) ................yield int(s+s[-2::-1], b) ............for y in range(b**(x-1), b**x): ................s = digits(y, b) ................yield int(s+s[::-1], b) A249155_list = [n for n in palQgen(8, 6) if palQ(n, 15)] # Chai Wah Wu, Nov 29 2014 CROSSREFS Cf. A007632, A060792, A249156, A249157, A249158. Sequence in context: A133476 A131023 A069514 * A101012 A048659 A065774 Adjacent sequences:  A249152 A249153 A249154 * A249156 A249157 A249158 KEYWORD nonn,base AUTHOR Ray Chandler, Oct 27 2014 STATUS approved

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Last modified May 11 03:49 EDT 2021. Contains 343784 sequences. (Running on oeis4.)