A051357 Chernoff sequence A006939 divided by 2.

1, 6, 180, 37800, 87318000, 2622159540000, 1338638666765400000, 12984380089637682726000000, 2896722619368127899492763620000000, 18740906719713843949122453226304292600000000

Offset

1,2

Links

G. C. Greubel, Table of n, a(n) for n = 1..37

Formula

a(n) = Product_{k=1..n} prime(k)^(n-k+1) / 2.

Mathematica

Table[Product[Prime[k]^(n - k + 1), {k, 1, n}]/2, {n, 1, 15}] (* G. C. Greubel, Oct 14 2018 *)

Prog

(PARI) for(n=1, 15, print1(prod(k=1, n, prime(k)^(n-k+1))/2, ", ")) \\ G. C. Greubel, Oct 14 2018
(Magma) [(&*[NthPrime(k)^(n-k+1): k in [1..n]])/2: n in [1..15]]; // G. C. Greubel, Oct 14 2018

Crossrefs

Sequence in context: A176730 A362174 A225776 * A251671 A064120 A041429

Adjacent sequences: A051354 A051355 A051356 * A051358 A051359 A051360

Keyword

easy,nonn

Author

Judson Neer

Status

approved