A351749 - OEIS

%I #5 Feb 20 2022 16:23:51

%S 0,5,28,5,3126,33,823544,5,28,3131,285311670612,33,302875106592254,

%T 823549,3154,5,827240261886336764178,33,1978419655660313589123980,

%U 3131,823572,285311670617,20880467999847912034355032910568,33,3126,302875106592259

%N a(n) = Sum_{p|n, p prime} sigma_p(p).

%F a(p^k) = p^p + 1, for p prime and k >= 1.

%e a(6) = 33; a(6) = Sum_{p|6, p prime} sigma_p(p) = sigma_2(2) + sigma_3(3) = (1^2 + 2^2) + (1^3 + 3^3) = 33.

%Y Cf. A023887 (sigma_n(n)).

%K nonn

%O 1,2

%A _Wesley Ivan Hurt_, Feb 17 2022