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A135105
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Digital sum (base the n-th prime) of n^5.
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1
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1, 4, 11, 16, 15, 12, 23, 44, 45, 40, 41, 72, 93, 98, 99, 48, 133, 108, 109, 160, 117, 172, 81, 120, 217, 176, 159, 102, 221, 144, 187, 262, 169, 304, 375, 276, 241, 158, 211, 316, 273, 72, 313, 320, 397, 406, 227, 582, 335, 236, 187, 460, 293, 274, 663, 178, 433, 538
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OFFSET
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1,2
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LINKS
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FORMULA
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a(n) = ds_prime(n)(n^5), where ds_prime(n) = digital sum base the n-th prime.
a(n) = n^5 - (prime(n)-1)*Sum_{k>0} ( floor(n^5/prime(n)^k) ).
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EXAMPLE
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a(2) = ds_prime(2)(2^5) = ds_3(32) = 1+0+1+2 = 4;
a(6) = ds_prime(5)(5^5) = ds_11(3125) = 2+9+3+1 = 15.
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MATHEMATICA
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Table[Total[IntegerDigits[n^5, Prime[n]]], {n, 60}] (* Harvey P. Dale, Jul 19 2013 *)
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PROG
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(PARI) a(n) = vecsum(digits(n^5, prime(n))); \\ Michel Marcus, Sep 24 2016
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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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