A035334 a(n) = smallest number which is not the sum of exactly 1 or a(n-1) earlier terms.
1, 2, 5, 3, 14, 4, 39, 6, 119, 7, 352, 8, 706, 9, 2104, 10, 4209, 11, 8419, 12, 24552, 13, 49106, 15, 188594, 16, 524494, 17, 1933822, 18, 5605163, 19, 15069555, 20
Offset: 1
Examples
a(5)=14 since all earlier numbers are either in list (1,2,3,5) or the sum of 3 terms from list (4=1+1+2, 6=2+2+2, ..., 12=2+5+5, 13=3+5+5).
Links
- Sean A. Irvine, Java program (github)
Crossrefs
Cf. A055456.
Extensions
a(9)-a(16) from Henry Bottomley, May 19 2000
a(17)-a(26) from Larry Reeves (larryr(AT)acm.org), May 08 2001
a(27)-a(32) from Sean A. Irvine, Oct 07 2020
a(33)-a(34) from Michael S. Branicky, Dec 06 2024