A136320 Terms of A047241 swapped in pairs.
3, 1, 9, 7, 15, 13, 21, 19, 27, 25, 33, 31, 39, 37, 45, 43, 51, 49, 57, 55, 63, 61, 69, 67, 75, 73, 81, 79, 87, 85, 93, 91, 99, 97, 105, 103, 111, 109, 117, 115, 123, 121, 129, 127, 135, 133, 141, 139, 147, 145, 153, 151, 159, 157, 165, 163, 171, 169, 177, 175, 183
Offset: 0
Links
- Index entries for linear recurrences with constant coefficients, signature (1,1,-1).
Formula
a(n) = 6*n - a(n-1) - 2 (with a(0)=3). - Vincenzo Librandi, Nov 24 2010
From Chai Wah Wu, Jul 28 2020: (Start)
a(n) = a(n-1) + a(n-2) - a(n-3) for n > 2.
G.f.: (5*x^2 - 2*x + 3)/((x - 1)^2*(x + 1)). (End)