%I #7 Apr 09 2016 16:11:40
%S 2,7,56,743,30746,773527,49783736,1837403019,160181560802,
%T 29532404308019,1666577516860962,360777399719461393,
%U 45691067858241526814,3477439299142731351087,518913689466371066697746,147680787468230866751370317,43490064769447225534580532962
%N a(n) = sigma(prime(n)^n) - phi(prime(n)^n).
%F a(n) = (2*prime(n)^n-prime(n)^(n-1)-1) / (prime(n)-1).
%F a(n) = (prime(n)^(n+1)-prime(n)^(n-1)*(prime(n)-1)^2-1) / (prime(n)-1).
%F a(n) = A051612(A062457(n)) = A000203(A062457(n)) - A000010(A062457(n)).
%p with(numtheory): A271440:=n->sigma(ithprime(n)^n)-phi(ithprime(n)^n): seq(A271440(n), n=1..30);
%t Table[DivisorSigma[1, Prime[n]^n] - EulerPhi[Prime[n]^n], {n, 20}]
%o (PARI) a(n) = sigma(prime(n)^n) - eulerphi(prime(n)^n); \\ _Altug Alkan_, Apr 08 2016
%Y Cf. A000010 (phi), A000040 (primes), A000203 (sigma), A051612, A062457.
%K nonn,easy
%O 1,1
%A _Wesley Ivan Hurt_, Apr 07 2016