A061887 n + largest square less than or equal to n; numbers in the range [2k^2,2k^2+2k] for some k.

0, 2, 3, 4, 8, 9, 10, 11, 12, 18, 19, 20, 21, 22, 23, 24, 32, 33, 34, 35, 36, 37, 38, 39, 40, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 128, 129

Offset

0,2

Links

Table of n, a(n) for n=0..65.

Formula

a(n) = n+[sqrt(n)]^2 = n+A048760(n) = 2n-A053186(n).

Example

a(15)=15+9=24; a(16)=16+16=32; a(17)=17+16=33.

Mathematica

Table[n+Floor[Sqrt[n]]^2, {n, 0, 70}] (* Harvey P. Dale, Aug 23 2012 *)

Crossrefs

Cf. A060984, A061885.

Sequence in context: A309314 A309326 A326701 * A005455 A047338 A069811

Adjacent sequences: A061884 A061885 A061886 * A061888 A061889 A061890

Keyword

nonn

Author

Henry Bottomley, May 12 2001

Status

approved