A256016
a(n) = n! * Sum_{k=0..n} k^n/k!.
Original entry on oeis.org
1, 1, 6, 57, 796, 15145, 374526, 11669665, 447595800, 20733553809, 1141067915290, 73552752257281, 5484203261135028, 467864288815609465, 45236104846954021014, 4915818294874879570305, 596044703812665607374256, 80118478395137652912476449, 11870487496575403846760198322
Offset: 0
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Join[{1}, Table[n!*Sum[k^n/k!,{k,0,n}],{n,1,20}]]
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a(n) = n!*sum(k=0, n, k^n/k!); \\ Michel Marcus, Aug 15 2020
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my(N=20, x='x+O('x^N)); Vec(serlaplace(sum(k=0, N, (k*x)^k/(k!*(1-k*x))))) \\ Seiichi Manyama, Aug 23 2022
A337001
a(n) = n! * Sum_{k=0..n} k^3 / k!.
Original entry on oeis.org
0, 1, 10, 57, 292, 1585, 9726, 68425, 547912, 4931937, 49320370, 542525401, 6510306540, 84633987217, 1184875823782, 17773137360105, 284370197765776, 4834293362023105, 87017280516421722, 1653328329812019577, 33066566596240399540, 694397898521048399601
Offset: 0
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Table[n! Sum[k^3/k!, {k, 0, n}], {n, 0, 21}]
nmax = 21; CoefficientList[Series[x (1 + 3 x + x^2) Exp[x]/(1 - x), {x, 0, nmax}], x] Range[0, nmax]!
a[0] = 0; a[n_] := a[n] = n (n^2 + a[n - 1]); Table[a[n], {n, 0, 21}]
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a(n) = n! * sum(k=0, n, k^3/k!); \\ Michel Marcus, Aug 12 2020
A337085
Square array T(n,k), n>=0, k>=0, read by antidiagonals, where T(n,k) = n! * Sum_{j=0..n} j^k/j!.
Original entry on oeis.org
1, 0, 2, 0, 1, 5, 0, 1, 4, 16, 0, 1, 6, 15, 65, 0, 1, 10, 27, 64, 326, 0, 1, 18, 57, 124, 325, 1957, 0, 1, 34, 135, 292, 645, 1956, 13700, 0, 1, 66, 345, 796, 1585, 3906, 13699, 109601, 0, 1, 130, 927, 2404, 4605, 9726, 27391, 109600, 986410, 0, 1, 258, 2577, 7804, 15145, 28926, 68425, 219192, 986409, 9864101
Offset: 0
Square array begins:
1, 0, 0, 0, 0, 0, 0, ...
2, 1, 1, 1, 1, 1, 1, ...
5, 4, 6, 10, 18, 34, 66, ...
16, 15, 27, 57, 135, 345, 927, ...
65, 64, 124, 292, 796, 2404, 7804, ...
326, 325, 645, 1585, 4605, 15145, 54645, ...
1957, 1956, 3906, 9726, 28926, 98646, 374526, ...
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T[n_, k_] := n! * Sum[If[j == k == 0, 1, j^k]/j!, {j, 0, n}]; Table[T[k, n-k], {n, 0, 9}, {k, 0, n}] // Flatten (* Amiram Eldar, Apr 29 2021 *)
A368575
a(n) = n! * Sum_{k=0..n} binomial(k+3,4) / k!.
Original entry on oeis.org
0, 1, 7, 36, 179, 965, 5916, 41622, 333306, 3000249, 30003205, 330036256, 3960436437, 51485675501, 720799459394, 10811991893970, 172991870307396, 2940861795230577, 52935512314156371, 1005774733968978364, 20115494679379576135, 422425388266971109461
Offset: 0
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my(N=30, x='x+O('x^N)); concat(0, Vec(serlaplace(x*sum(k=0, 3, binomial(3, k)*x^k/(k+1)!)*exp(x)/(1-x))))
A368717
a(n) = n! * Sum_{k=0..n} (-1)^(n-k) * k^4 / k!.
Original entry on oeis.org
0, 1, 14, 39, 100, 125, 546, -1421, 15464, -132615, 1336150, -14683009, 176216844, -2290790411, 32071104170, -481066511925, 7697064256336, -130850092274191, 2355301661040414, -44750731559637545, 895014631192910900, -18795307255050934419
Offset: 0
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f:= proc(n) option remember;
- n*procname(n-1)+n^4
end proc:
f(0):= 0:
seq(f(i),i=0..30); # Robert Israel, May 13 2025
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Table[-n + 2*n^2 + n^3 + (-1)^n*n*Subfactorial[n-1], {n, 0, 20}] (* Vaclav Kotesovec, Jul 18 2025 *)
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my(N=30, x='x+O('x^N)); concat(0, Vec(serlaplace(sum(k=0, 4, stirling(4, k, 2)*x^k)*exp(x)/(1+x))))
A374844
a(n) = n! * Sum_{k=1..n} k^k / k!.
Original entry on oeis.org
0, 1, 6, 45, 436, 5305, 78486, 1372945, 27760776, 637267473, 16372674730, 465411092641, 14501033559948, 491388542871577, 17991446425760094, 707765586767260785, 29770993461985724176, 1333347150740094075169, 63346656788618230928466
Offset: 0
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a:= proc(n) a(n):= n*a(n-1) + n^n end: a(0):= 0:
seq(a(n), n=0..23); # Alois P. Heinz, Jul 22 2024
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a(n) = n!*sum(k=1, n, k^k/k!);
Showing 1-6 of 6 results.
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