A336958
E.g.f.: 1 / (exp(2*x) - x).
Original entry on oeis.org
1, -1, -2, 10, 24, -312, -560, 19472, 6272, -1994624, 4072704, 299059968, -1635814400, -60723321856, 628215191552, 15716076562432, -274420622327808, -4900668238036992, 140182198527655936, 1717697481518809088, -83651335147070685184, -590374211868638314496
Offset: 0
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nmax = 21; CoefficientList[Series[1/(Exp[2 x] - x), {x, 0, nmax}], x] Range[0, nmax]!
Table[n! Sum[(-2 (n - k + 1))^k/k!, {k, 0, n}], {n, 0, 21}]
a[0] = 1; a[n_] := a[n] = -n a[n - 1] - Sum[Binomial[n, k] 2^k a[n - k], {k, 2, n}]; Table[a[n], {n, 0, 21}]
A351791
Square array T(n,k), n >= 0, k >= 0, read by antidiagonals downwards, where T(n,k) = n! * Sum_{j=0..n} (-k * (n-j))^j/j!.
Original entry on oeis.org
1, 1, 1, 1, 1, 2, 1, 1, 0, 6, 1, 1, -2, -3, 24, 1, 1, -4, -6, -4, 120, 1, 1, -6, -3, 40, 25, 720, 1, 1, -8, 6, 132, 120, 114, 5040, 1, 1, -10, 21, 248, -375, -1872, -287, 40320, 1, 1, -12, 42, 364, -2120, -8298, -3920, -4152, 362880, 1, 1, -14, 69, 456, -5655, -12144, 86121, 155776, -1647, 3628800
Offset: 0
Square array begins:
1, 1, 1, 1, 1, 1, ...
1, 1, 1, 1, 1, 1, ...
2, 0, -2, -4, -6, -8, ...
6, -3, -6, -3, 6, 21, ...
24, -4, 40, 132, 248, 364, ...
120, 25, 120, -375, -2120, -5655, ...
Main diagonal gives (-1)^n *
A302398(n).
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T[n_, k_] := n!*(1 + Sum[(-k*(n - j))^j/j!, {j, 1, n}]); Table[T[k, n - k], {n, 0, 10}, {k, 0, n}] // Flatten (* Amiram Eldar, Feb 19 2022 *)
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T(n, k) = n!*sum(j=0, n, (-k*(n-j))^j/j!);
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T(n, k) = if(n==0, 1, n*sum(j=0, n-1, (-k)^(n-1-j)*binomial(n-1, j)*T(j, k)));
Showing 1-2 of 2 results.