A131133 a(0)=1; for n > 0, a(n) = (1/n + 1/a(n-1))*lcm(n, a(n-1)).

1, 2, 2, 5, 9, 14, 10, 17, 25, 34, 22, 3, 5, 18, 16, 31, 47, 64, 41, 60, 4, 25, 47, 70, 47, 72, 49, 76, 26, 55, 17, 48, 5, 38, 36, 71, 107, 144, 91, 10, 5, 46, 44, 87, 131, 176, 111, 158, 103, 152, 101, 152, 51, 104, 79, 134, 95, 8, 33, 92, 38, 99, 161, 32, 3, 68, 67, 2, 35, 104

Offset: 0

Author

Leroy Quet, Jun 17 2007

Keywords

• nonn

Comments

Equivalently, a(0)=1; a(n) = (a(n-1)+n)/gcd(n,a(n-1)). - Ctibor O. Zizka, Feb 15 2008

Links

• Harvey P. Dale, Table of n, a(n) for n = 0..1000

Crossrefs

Cf. A131134.

Programs

Maple

a[0] := 1; for n to 70 do a[n] := (1/n+1/a[n-1])*lcm(n, a[n-1]) end do; seq(a[n], n = 0 .. 70) # Emeric Deutsch, Jun 21 2007

Mathematica

nxt[{n_,a_}]:={n+1,(1/(n+1)+1/a)LCM[n+1,a]}; Transpose[NestList[nxt,{0,1},70]][[2]] (* Harvey P. Dale, Mar 04 2013 *)

Extensions

More terms from Emeric Deutsch, Jun 21 2007

Edited by N. J. A. Sloane, May 16 2008 at the suggestion of R. J. Mathar