A080034 a(n) is taken to be the smallest positive integer not already present which is consistent with the condition "n is a member of the sequence if and only if a(n) is congruent to 3 mod 4".

1, 3, 4, 7, 11, 6, 15, 19, 9, 23, 12, 27, 31, 14, 35, 39, 17, 43, 20, 47, 51, 22, 55, 59, 25, 63, 28, 67, 71, 30, 75, 79, 33, 83, 36, 87, 91, 38, 95, 99, 41, 103, 44, 107, 111, 46, 115, 119, 49, 123, 52, 127, 131, 54, 135, 139, 57, 143, 60, 147, 151, 62, 155, 159, 65, 163

Offset: 0

Author

N. J. A. Sloane, Mar 14 2003

Keywords

• easy
• nonn

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

Equals A080033(n+1)-1.

Formula

From Chai Wah Wu, Sep 27 2016: (Start)

a(n) = 2*a(n-8) - a(n-16) for n > 15.

G.f.: (x^15 + 5*x^14 + 2*x^13 + 9*x^12 + 13*x^11 + 4*x^10 + 17*x^9 + 7*x^8 + 19*x^7 + 15*x^6 + 6*x^5 + 11*x^4 + 7*x^3 + 4*x^2 + 3*x + 1)/(x^16 - 2*x^8 + 1). (End)

Extensions

More terms from Matthew Vandermast, Mar 23 2003