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A271440
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a(n) = sigma(prime(n)^n) - phi(prime(n)^n).
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1
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2, 7, 56, 743, 30746, 773527, 49783736, 1837403019, 160181560802, 29532404308019, 1666577516860962, 360777399719461393, 45691067858241526814, 3477439299142731351087, 518913689466371066697746, 147680787468230866751370317, 43490064769447225534580532962
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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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a(n) = (2*prime(n)^n-prime(n)^(n-1)-1) / (prime(n)-1).
a(n) = (prime(n)^(n+1)-prime(n)^(n-1)*(prime(n)-1)^2-1) / (prime(n)-1).
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MAPLE
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with(numtheory): A271440:=n->sigma(ithprime(n)^n)-phi(ithprime(n)^n): seq(A271440(n), n=1..30);
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MATHEMATICA
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Table[DivisorSigma[1, Prime[n]^n] - EulerPhi[Prime[n]^n], {n, 20}]
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PROG
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(PARI) a(n) = sigma(prime(n)^n) - eulerphi(prime(n)^n); \\ Altug Alkan, Apr 08 2016
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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STATUS
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approved
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