A081260 a(1)=4; for n>1, a(n) is taken to be the third-smallest integer greater than a(n-1) such that the condition "n is a member of the sequence if and only if a(n) is odd" is satisfied.

4, 10, 16, 21, 26, 32, 38, 44, 50, 55, 60, 66, 72, 78, 84, 89, 94, 100, 106, 112, 117, 122, 128, 134, 140, 145, 150, 156, 162, 168, 174, 179, 184, 190, 196, 202, 208, 213, 218, 224, 230, 236, 242, 247, 252, 258, 264, 270, 276, 281, 286, 292, 298, 304, 309, 314

Offset: 1

Author

Matthew Vandermast, Mar 14 2003

Keywords

• easy
• nonn

Examples

			a(1)=4, implying that the fourth term is the first odd member of the sequence; hence a(2) and a(3) are even. The third-smallest even integer greater than 4 is 10; therefore a(2)=10. The third-smallest integers that can satisfy the given condition if taken as a(3) and a(4) are 16 and 21, respectively.
		

Links

• B. Cloitre, N. J. A. Sloane and M. J. Vandermast, Numerical analogues of Aronson's sequence, J. Integer Seqs., Vol. 6 (2003), #03.2.2.
• B. Cloitre, N. J. A. Sloane and M. J. Vandermast, Numerical analogues of Aronson's sequence (math.NT/0305308)

Crossrefs

Cf. A079000, A080753.