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A249155
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Palindromic in bases 6 and 15.
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4
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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
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OFFSET
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1,3
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COMMENTS
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LINKS
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EXAMPLE
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301 is a term since 301 = 1221 base 6 and 301 = 151 base 15.
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MATHEMATICA
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palQ[n_Integer, base_Integer] := Block[{idn = IntegerDigits[n, base]}, idn == Reverse[idn]]; Select[Range[10^6] - 1, palQ[#, 6] && palQ[#, 15] &]
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PROG
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(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)
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CROSSREFS
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KEYWORD
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nonn,base
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AUTHOR
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STATUS
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approved
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