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A334557
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Numbers m such that m = p^2 + k^2, with p > 0, where p = A007954(m) = the product of digits of m.
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3
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1, 13, 41, 61, 125, 212, 281, 613, 1156, 1424, 2225, 3232, 3316, 4113, 11125, 11281, 11525, 12816, 14913, 16317, 16441, 19125, 21284, 21625, 24128, 25216, 27521, 31525, 53125, 56116, 61321, 65161, 71325, 82116, 82217, 83521, 84313, 111812, 113125, 113625, 115336, 115681, 117125, 118372
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OFFSET
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1,2
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LINKS
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EXAMPLE
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13 is a term as p = 1*3 = 3 and 13 = 3^2 + 2^2.
281 is a term as p = 2*8*1 = 16 and 281 = 16^2 + 5^2.
118372 is a term as p = 1*1*8*3*7*2 = 336 and 118372 = 336^2 + 74^2.
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PROG
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(PARI) isok(m) = my(p=vecprod(digits(m))); p && issquare(m - p^2); \\ Michel Marcus, May 06 2020
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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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