cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A374428 Triangle read by rows: T(n, k) = n! * 2^k * hypergeom([-k], [-n], 1/2).

Original entry on oeis.org

1, 1, 3, 2, 5, 13, 6, 14, 33, 79, 24, 54, 122, 277, 633, 120, 264, 582, 1286, 2849, 6331, 720, 1560, 3384, 7350, 15986, 34821, 75973, 5040, 10800, 23160, 49704, 106758, 229502, 493825, 1063623, 40320, 85680, 182160, 387480, 824664, 1756086, 3741674, 7977173, 17017969
Offset: 0

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Author

Peter Luschny, Jul 28 2024

Keywords

Crossrefs

Cf. A010844 (main diagonal), A374427.

Programs

  • Mathematica
    T[n_, k_] := n! 2^k Hypergeometric1F1[-k, -n, 1/2];
    (* Alternative: *)
    T[n_, k_] := Sum[2^(k - j)*Binomial[k, k - j]*((n - j)!), {j, 0, k}];
    Table[T[n, k], {n, 0, 8}, {k, 0, n}] // Flatten (* Detlef Meya, Aug 12 2024 *)

Formula

T(n, k) = Sum_{j=0..k} 2^(k - j)*binomial(k, k - j)*(n - j)!. - Detlef Meya, Aug 12 2024