A081025 Variation on Ulam numbers: a(1) = 1; a(2) = 2; for n>2, a(n) is smallest (n odd) or largest (n even) new number that is the sum of two distinct earlier terms.

1, 2, 3, 5, 4, 9, 8, 17, 14, 31, 15, 48, 21, 79, 30, 127, 40, 206, 41, 333, 47, 539, 53, 872, 63, 1411, 66, 2283, 75, 3694, 76, 5977, 82, 9671, 86, 15648, 92, 25319, 99, 40967, 102, 66286, 108, 107253, 115, 173539, 118, 280792, 121, 454331, 131, 735123, 143

Offset: 1

Author

David W. Wilson, Mar 02 2003

Keywords

• nonn

References

• Suggested by Dan Asimov in post to math-fun, 2/11/2003.

Crossrefs

Cf. A002858, A081026.