A103520 a(1) = 1, a(n) = product of n successive numbers starting with a(n-1) + 1.

1, 6, 504, 65813284680, 1234718152224069224489356305213161520251951242625962440

Offset

1,2

Comments

a(6) has 325 digits and a(7) has 2272 digits. - Harvey P. Dale, Aug 23 2014

Links

Table of n, a(n) for n=1..5.

Formula

a(n+1) = !{a(n)+n +1}/!{a(n)}

Example

a(2) = 2*3 = 6, a(3) = 7*8*9 = 504.

Mathematica

nxt[{n_, a_}]:={n+1, Times@@Range[a+1, a+1+n]}; Transpose[NestList[nxt, {1, 1}, 5]][[2]] (* Harvey P. Dale, Aug 23 2014 *)

Crossrefs

Cf. A103519.

Sequence in context: A278775 A013975 A272094 * A223050 A290937 A364482

Adjacent sequences: A103517 A103518 A103519 * A103521 A103522 A103523

Keyword

easy,nonn

Author

Amarnath Murthy, Feb 10 2005

Extensions

More terms from Olaf Voß, Feb 26 2005. (The next term is too large to include.)

Status

approved