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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.
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%I #3 Mar 30 2012 18:35:41

%S 1,2,3,5,4,9,8,17,14,31,15,48,21,79,30,127,40,206,41,333,47,539,53,

%T 872,63,1411,66,2283,75,3694,76,5977,82,9671,86,15648,92,25319,99,

%U 40967,102,66286,108,107253,115,173539,118,280792,121,454331,131,735123,143

%N 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.

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

%Y Cf. A002858, A081026.

%K nonn

%O 1,2

%A _David W. Wilson_, Mar 02 2003