A334767 a(n) = Product_{k=1..n} d(2*k), where d() is the number of divisors function A000005.

2, 6, 24, 96, 384, 2304, 9216, 46080, 276480, 1658880, 6635520, 53084160, 212336640, 1274019840, 10192158720, 61152952320, 244611809280, 2201506283520, 8806025134080, 70448201072640, 563585608581120, 3381513651486720, 13526054605946880

Offset

1,1

Links

Table of n, a(n) for n=1..23.

Example

a(4) = d(2)*d(4)*d(6)*d(8) = 2*3*4*4 = 96.

Mathematica

Rest @ FoldList[Times, 1, DivisorSigma[0, Range[2, 40, 2]]] (* Amiram Eldar, May 10 2020 *)

Prog

(PARI) a(n) = prod(k=1, n, numdiv(2*k)); \\ Michel Marcus, May 10 2020

Crossrefs

Cf. A000005, A066843, A099777.

Sequence in context: A179356 A179363 A084509 * A323260 A147915 A147906

Adjacent sequences: A334764 A334765 A334766 * A334768 A334769 A334770

Keyword

nonn

Author

Ctibor O. Zizka, May 10 2020

Status

approved