A183292 Complement of A055999.

1, 2, 3, 5, 6, 7, 8, 10, 11, 12, 13, 14, 16, 17, 18, 19, 20, 21, 23, 24, 25, 26, 27, 28, 29, 31, 32, 33, 34, 35, 36, 37, 38, 40, 41, 42, 43, 44, 45, 46, 47, 48, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 86, 87, 88, 89, 90

Offset: 1

Author

Clark Kimberling, Jan 03 2011

Keywords

• nonn

Crossrefs

Cf. A055999.

Programs

Mathematica

a=1/2; b=7/2;
F[n_]:=a*n^2+b*n;
R[n_]:=(n/a+((b-1)/(2a))^2)^(1/2);
G[n_]:=n-1+Ceiling[R[n]-(b-1)/(2a)];
Table[F[n], {n,60}]
Table[G[n], {n,100}]

PARI

a(n)=n-1+ceil(sqrt(8*n+25)/2-5/2) \\ Charles R Greathouse IV, Jan 20 2016

Formula

(See the Mathematica code.)