A345465
a(n) = Sum_{d|n} (d!)^d.
Original entry on oeis.org
1, 5, 217, 331781, 24883200001, 139314069504000221, 82606411253903523840000001, 6984964247141514123629140377600331781, 109110688415571316480344899355894085582848000000217, 395940866122425193243875570782668457763038822400000000024883200005
Offset: 1
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Total/@Table[((Divisors[n])!)^Divisors[n],{n,10}] (* Harvey P. Dale, Apr 24 2022 *)
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a(n) = sumdiv(n, d, d!^d);
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my(N=20, x='x+O('x^N)); Vec(sum(k=1, N, (k!*x)^k/(1-x^k)))
A346196
a(n) = Sum_{d|n} (d!)^n.
Original entry on oeis.org
1, 5, 217, 331793, 24883200001, 139314069504046721, 82606411253903523840000001, 6984964247141514123629140487675314433, 109110688415571316480344899355894085582848010077697, 395940866122425193243875570782668457763038823019173642240000001025
Offset: 1
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a[n_] := DivisorSum[n, (#!)^n &]; Array[a, 10] (* Amiram Eldar, Aug 30 2023 *)
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a(n) = sumdiv(n, d, d!^n);
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my(N=20, x='x+O('x^N)); Vec(sum(k=1, N, (k!*x)^k/(1-(k!*x)^k)))
A358279
a(n) = Sum_{d|n} (d-1)! * d^(n/d).
Original entry on oeis.org
1, 3, 7, 29, 121, 747, 5041, 40433, 362935, 3629433, 39916801, 479006531, 6227020801, 87178326609, 1307674371487, 20922790212353, 355687428096001, 6402373709021811, 121645100408832001, 2432902008212950169, 51090942171709691335, 1124000727778046766849
Offset: 1
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a[n_] := DivisorSum[n, (# - 1)! * #^(n/#) &]; Array[a, 22] (* Amiram Eldar, Aug 30 2023 *)
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a(n) = sumdiv(n, d, (d-1)!*d^(n/d));
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my(N=30, x='x+O('x^N)); Vec(sum(k=1, N, k!*x^k/(1-k*x^k)))
Showing 1-3 of 3 results.