A082573 a(1)=1, a(n)=ceiling(n*(a(n-1)+3/a(n-1))).

1, 8, 26, 105, 526, 3157, 22100, 176801, 1591210, 15912101, 175033112, 2100397345, 27305165486, 382272316805, 5734084752076, 91745356033217, 1559671052564690, 28074078946164421, 533407499977124000, 10668149999542480001

Offset

1,2

Comments

More generally if m is an integer >=3 and a(1)=1, a(n)=ceiling(n*(a(n-1)+m/a(n-1))) there is a closed formula for a(n) namely : a(n)=floor(n!*(e+m-4/3))

Links

Table of n, a(n) for n=1..20.

Formula

a(n)=floor(n!*(exp(1)+5/3))

Mathematica

nxt[{n_, a_}]:={n+1, Ceiling[(n+1)(a+3/a)]}; Transpose[NestList[nxt, {1, 1}, 20]][[2]] (* Harvey P. Dale, Sep 12 2013 *)

Crossrefs

Sequence in context: A173365 A261971 A140788 * A112645 A220713 A260962

Adjacent sequences: A082570 A082571 A082572 * A082574 A082575 A082576

Keyword

nonn

Author

Benoit Cloitre, May 06 2003

Extensions

Offset changed by Harvey P. Dale, Sep 12 2013

Status

approved