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

1,2

References

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

Links

Table of n, a(n) for n=1..53.

Crossrefs

Cf. A002858, A081026.

Sequence in context: A302850 A338253 A060030 * A329811 A245607 A251604

Adjacent sequences: A081022 A081023 A081024 * A081026 A081027 A081028

Keyword

nonn

Author

David W. Wilson, Mar 02 2003

Status

approved