A268584 a(0)=0; a(1)=0. For m>=1 : a(2*m) = 2*m-2-i, a(2*m+1) = 2*m-2-i, where i (0<=i<=2*m-4) is the largest number such that a(2*m-2)-a(i)=0 AND a(2*m-1)-a(i+1)=0, or a(2*m)=0 AND a(2*m+1)=0 if no such i exists.

0, 0, 0, 0, 2, 2, 0, 0, 4, 4, 0, 0, 4, 4, 4, 4, 2, 2, 12, 12, 0, 0, 10, 10, 0, 0, 4, 4, 12, 12, 10, 10, 8, 8, 0, 0, 10, 10, 6, 6, 0, 0, 6, 6, 4, 4, 18, 18, 0, 0, 8, 8, 18, 18, 6, 6, 12, 12, 28, 28, 0, 0, 12, 12, 6, 6, 10, 10, 30, 30, 0, 0, 10, 10, 6, 6, 10, 10, 4, 4, 34, 34, 0, 0, 12, 12, 22, 22, 0, 0, 6, 6, 16, 16, 0, 0, 6, 6, 6, 6, 2, 2, 84, 84, 0, 0

Offset

0,5

Links

Table of n, a(n) for n=0..105.

Formula

a(2*n-2) = a(2*n-1) = 2 * A181391(n).

Example

a(0)=0 ; a(1)=0.
a(2)=0 ; a(3)=0. By definition, because no such i exists.
a(4)=(2-0)=2 ; a(5)=(3-1)=2.
a(6)=0 ; a(7)=0. By definition, because no such i exists.
a(8)=(6-2)=4 ; a(9)=(7-3)=4.
a(10)=0 ; a(11)=0. By definition, because no such i exists.
and so on.

Crossrefs

Cf. A181391, A267794.

Sequence in context: A300776 A301400 A134315 * A119332 A335683 A089262

Adjacent sequences: A268581 A268582 A268583 * A268585 A268586 A268587

Keyword

nonn

Author

Ctibor O. Zizka, Feb 07 2016

Extensions

Name corrected by Andrei Zabolotskii, May 06 2026

Status

approved