A183296 Complement of A005476.

1, 3, 4, 5, 6, 7, 8, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85

Offset

1,2

Links

Table of n, a(n) for n=1..80.

Formula

(See the Mathematica code.)

a(n) = n+m if n > m*(5*m-3)/2 and a(n) = n+m-1 otherwise, where m = floor(sqrt(2*n/5))+1. - Chai Wah Wu, Nov 05 2025

Mathematica

  a=5/2; b=-1/2;
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}]

Prog

(Python)
from math import isqrt
def A183296(n): return n+(m:=isqrt((k:=n<<1)//5)+1)-(k<=m*(5*m-3)) # Chai Wah Wu, Nov 05 2025

Crossrefs

Cf. A005476.

Sequence in context: A392568 A329254 A359003 * A138928 A116587 A057903

Adjacent sequences: A183293 A183294 A183295 * A183297 A183298 A183299

Keyword

nonn

Author

Clark Kimberling, Jan 03 2011

Status

approved