A328987 The sequence C(n) defined in the comments (A and B smallest missing numbers, offset 0).
3, 10, 15, 20, 27, 32, 39, 44, 51, 56, 61, 68, 73, 80, 85, 90, 97, 102, 109, 114, 119, 126, 131, 138, 143, 150, 155, 160, 167, 172, 179, 184, 189, 196, 201, 208, 213, 220, 225, 230, 237, 242, 249, 254, 259, 266, 271, 278, 283, 290, 295, 300, 307, 312, 319
Offset: 0
Keywords
Examples
The initial terms are: n: 0, 1, 2, 3, 4, 5, 6, 7, 8. 9. 10. ... a: 1, 4, 6, 8, 11, 13, 16, 18, 21, 23,25, ... b: 2, 5, 7, 9, 12, 14, 17, 19, 22, 24,26, ... c: 3, 10, 15, 20, 27, 32, 39, 44, 51, 56, 61, 68, 73, ...
Formula
Conjectures from Colin Barker, Nov 08 2019: (Start)
G.f.: (3 + 7*x + 5*x^2 + 5*x^3 + 7*x^4 + 5*x^5 + 7*x^6 + 5*x^7 + 7*x^8 + 5*x^9 + 5*x^10 + 7*x^11 + 2*x^12 - 2*x^20 + 2*x^21) / (1 - x - x^12 + x^13).
a(n) = a(n-1) + a(n-12) - a(n-13) for n>21.
(End)
Conjecture: a(n) ~ 35*n/6. - Stefano Spezia, Nov 02 2021
Comments