A179753 Integers (2k)-1..0 followed by integers (2k)+1..0 and so on.

1, 0, 3, 2, 1, 0, 5, 4, 3, 2, 1, 0, 7, 6, 5, 4, 3, 2, 1, 0, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0

Offset: 1

Author

Antti Karttunen, Aug 03 2010

Keywords

• nonn

Programs

Mathematica

Flatten[Table[Range[2n-1,0,-1],{n,10}]] (* Harvey P. Dale, Oct 08 2012 *)

Python

from math import isqrt
def A179753(n): return (k:=(m:=isqrt(n))+(n>m*(m+1)))*(1+k)-n # Chai Wah Wu, Jun 06 2025

Formula

a(n) = (2*A000194(n)) - A074294(n).