A128977 a(0)=a(1)=1; a(n) = lcm(a(n-1) + a(n-2), n).

1, 1, 2, 3, 20, 115, 270, 385, 5240, 5625, 21730, 300905, 1290540, 20688785, 307710550, 328399335, 10177758160, 178604677415, 377564871150, 10567221422735, 43779145175540, 1141273698563775, 26071162562264930

Offset

0,3

Links

Table of n, a(n) for n=0..22.

Example

Since a(4)=20 and a(5)=115, we have a(6) = lcm(135,6) = 270.

Maple

a[0]:=1: a[1]:=1: for n from 2 to 26 do a[n]:=lcm(a[n-1]+a[n-2], n) od: seq(a[n], n=0..26); # Emeric Deutsch, May 06 2007

Mathematica

RecurrenceTable[{a[0]==a[1]==1, a[n]==LCM[a[n-1]+a[n-2], n]}, a, {n, 30}] (* Harvey P. Dale, Apr 17 2012 *)

Crossrefs

Cf. A113925.

Sequence in context: A165960 A125763 A042441 * A375683 A069323 A356884

Adjacent sequences: A128974 A128975 A128976 * A128978 A128979 A128980

Keyword

nonn

Author

Leroy Quet, Apr 29 2007

Extensions

More terms from Emeric Deutsch, May 06 2007

Status

approved