A378802 a(n) = n * binomial(4*n, n).

0, 4, 56, 660, 7280, 77520, 807576, 8288280, 84146400, 847289520, 8476605280, 84362730452, 836022413616, 8255176274800, 81266247493200, 797911337890800, 7816430993273280, 76417576884236016, 745777615780501920, 7266758081613043600, 70706322844243486400, 687103929058903836480

Offset

0,2

Links

Amiram Eldar, Table of n, a(n) for n = 0..500

Necdet Batir and Anthony Sofo, On some series involving reciprocals of binomial coefficients, Appl. Math. Comp., Vol. 220 (2013), pp. 331-338.

Formula

a(n) = n * A005810(n).

a(n) = A374522(n) + n.

a(n) == 0 (mod 4).

Sum_{n>=1} 1/a(n) = A225847.

Sum_{n>=1} (-1)^n/a(n) = A229703.

Mathematica

a[n_] := n * Binomial[4*n, n]; Array[a, 25, 0]

Prog

(PARI) a(n) = n * binomial(4*n, n);

Crossrefs

Cf. A005810, A225847, A229703, A374522.

Sequence in context: A191466 A333294 A130219 * A222687 A111874 A297944

Adjacent sequences: A378799 A378800 A378801 * A378803 A378804 A378805

Keyword

nonn,easy,new

Author

Amiram Eldar, Dec 07 2024

Status

approved