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A259251
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a(n) = 1 + sigma(n) + sigma(n)^2 + sigma(n)^3 + sigma(n)^4 + sigma(n)^5 + sigma(n)^6.
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3
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7, 1093, 5461, 137257, 55987, 3257437, 299593, 12204241, 5229043, 36012943, 3257437, 499738093, 8108731, 199411801, 199411801, 917087137, 36012943, 3611342281, 67368421, 5622910567, 1108378657, 2238976117, 199411801, 47446779661, 917087137, 5622910567
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OFFSET
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1,1
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LINKS
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FORMULA
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MAPLE
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with(numtheory): A259251:=n->1 + sigma(n) + sigma(n)^2 + sigma(n)^3 + sigma(n)^4 + sigma(n)^5 + sigma(n)^6: seq(A259251(n), n=1..50); # Wesley Ivan Hurt, Jul 09 2015
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MATHEMATICA
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Table[1 + DivisorSigma[1, n] + DivisorSigma[1, n]^2 + DivisorSigma[1, n]^3 + DivisorSigma[1, n]^4 + DivisorSigma[1, n]^5 + DivisorSigma[1, n]^6, {n, 10000}]
Table[Cyclotomic[7, DivisorSigma[1, n]], {n, 10000}]
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PROG
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(PARI) vector(30, n, polcyclo(7, sigma(n))) \\ Michel Marcus, Jun 23 2015
(Magma) [1 + SumOfDivisors(n) + SumOfDivisors(n)^2 + SumOfDivisors(n)^3 + SumOfDivisors(n)^4 + SumOfDivisors(n)^5 + SumOfDivisors(n)^6: n in [1..50]]; // Vincenzo Librandi, Jun 26 2015
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CROSSREFS
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Cf. A000203 (sum of divisors of n).
Cf. A259252 (indices of primes in this sequence), A259253 (corresponding primes).
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KEYWORD
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easy,nonn
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AUTHOR
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STATUS
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approved
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