A007807 - OEIS

A007807

A variation on Euclid: a(n)=g(n)-1, where g(0)=0, g(1)=1, g(n+1)=g(n)(g(n-1)+1).

0, 0, 1, 3, 11, 59, 779, 47579, 37159979, 1768109008379, 65702897157329640779, 116169884340604934905464739377179, 7632697963609645128663145969343357330533515068777579

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,4

LINKS

Andrew Howroyd, Table of n, a(n) for n = 1..19

M. E. Mays, Iterating the division algorithm, Fib. Quart., 25 (1987), 204-213.

FORMULA

a(n) = A005831(n) - 1 for all n>0. - Michael Somos, Jan 17 2015

PROG

(PARI) {a(n) = if( n<4, n==3, -1 + (1 + a(n-1)) * (2 + a(n-2)))}; /* Michael Somos, Jan 17 2015 */

CROSSREFS

Cf. A005831.

Sequence in context: A276746 A112368 A152796 * A075201 A362911 A136440

Adjacent sequences: A007804 A007805 A007806 * A007808 A007809 A007810

KEYWORD

nonn

AUTHOR

Mike Mays (mays(AT)math.wvu.edu)

STATUS

approved