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a(n) = Sum_{d|n} d^(d+n+1).
3

%I #15 Oct 04 2023 03:51:15

%S 1,33,2188,262273,48828126,13060753578,4747561509944,2251799880796161,

%T 1350851717674586413,1000000000152587898818,895430243255237372246532,

%U 953962166441299506564257602,1192533292512492016559195008118

%N a(n) = Sum_{d|n} d^(d+n+1).

%H Seiichi Manyama, <a href="/A294773/b294773.txt">Table of n, a(n) for n = 1..214</a>

%t a[n_] := DivisorSum[n, #^(# + n + 1) &]; Array[a, 13] (* _Amiram Eldar_, Oct 04 2023 *)

%o (PARI) {a(n) = sumdiv(n, d, d^(d+n+1))}

%Y Cf. A294645, A294704, A294757.

%K nonn

%O 1,2

%A _Seiichi Manyama_, Nov 08 2017