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A119496
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Numbers n such that 2^n, 3^n, 5^n and 7^n have even digit sum.
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0
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15, 64, 83, 90, 106, 107, 120, 122, 135, 168, 173, 180, 181, 185, 193, 198, 222, 229, 239, 242, 289, 299, 347, 356, 364, 369, 407, 424, 447, 458, 462, 470, 479, 481, 503, 542, 552, 568, 580, 583, 607, 612, 648, 657, 676, 683, 684, 688, 742, 758, 787
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OFFSET
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1,1
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LINKS
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EXAMPLE
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{2^15,3^15,5^15,7^15}={32768,14348907,30517578125,4747561509943} with even digit sum {26,36,44,64}.
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MATHEMATICA
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Select[Range[800], AllTrue[Total/@(IntegerDigits/@({2, 3, 5, 7}^#)), EvenQ]&] (* Harvey P. Dale, Oct 13 2022 *)
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PROG
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(PARI) isok(n) = !(sumdigits(2^n) % 2) && !(sumdigits(3^n) % 2) && !(sumdigits(5^n) % 2) && !(sumdigits(7^n) % 2); \\ Michel Marcus, Oct 10 2013
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CROSSREFS
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KEYWORD
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base,nonn
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AUTHOR
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STATUS
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approved
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