A157248 'Greedy' sequence formed by summing unit fractions until the sum is 1, and repeating using up the 'left over' fractions.

1, 2, 3, 6, 4, 5, 7, 8, 9, 10, 15, 230, 57960, 11, 12, 13, 14, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 1544, 8242614, 92401258430373, 36895712779713620978746324067

Offset: 1

Author

Jeremy Gardiner, Feb 25 2009

Keywords

• nonn

Comments

Subsequence of starting elements of each pass may be related to A002387 1,2,4,11,31,83,... - David W. Wilson

Examples

			1/2+1/3+1/6=1
		

References

• H. Ibstedt, Computer Analysis of Number Sequences, American Research Press, 1998; Chapter VI.2 Integers represented as sums of terms of the harmonic series.

Links

• Jeremy Gardiner, Table of n, a(n) for n=1..94
• K. S. Brown's Mathpages, The Greedy Algorithm for Unit Fractions

Crossrefs

Cf. A192881.

Programs

PARI

{r=1;u=[];l=1;for(n=1,99,while(setsearch(u,l),l++);m=ceil(1/r);while(setsearch(u,m),m++);print1(m",");r-=1/m;r||r=1;u=setunion(u,Set(m)))} \\ M. F. Hasler