A276792 First differences of A003146.

7, 6, 7, 4, 7, 6, 7, 7, 6, 7, 4, 7, 6, 7, 6, 7, 4, 7, 6, 7, 7, 6, 7, 4, 7, 6, 7, 4, 7, 6, 7, 7, 6, 7, 4, 7, 6, 7, 6, 7, 4, 7, 6, 7, 7, 6, 7, 4, 7, 6, 7, 7, 6, 7, 4, 7, 6, 7, 6, 7, 4, 7, 6, 7, 7, 6, 7, 4, 7, 6, 7, 4, 7, 6, 7, 7, 6, 7, 4, 7, 6, 7, 6, 7, 4, 7, 6, 7, 7, 6, 7, 4, 7, 6, 7, 6, 7, 4, 7

Offset: 1

Author

N. J. A. Sloane, Oct 27 2016

Keywords

• nonn
• easy

Links

• Rémy Sigrist, Table of n, a(n) for n = 1..10608
• Elena Barcucci, Luc Belanger and Srecko Brlek, On tribonacci sequences, Fib. Q., 42 (2004), 314-320. See page 317.
• F. Michel Dekking, Jeffrey Shallit, and N. J. A. Sloane, Queens in exile: non-attacking queens on infinite chess boards, Electronic J. Combin., 27:1 (2020), #P1.52.

Crossrefs

Cf. A003144, A003145, A003146, A080843, A276788, A276789.

Formula

a(n) = A003146(n+1) - A003146(n), for n >= 1.

a(n) = A276788(n) + A276789(n) + 1, for n >= 1.

a(n+1) = 7 - t(n)*(t(n) + 1)/2, n >= 0, where t(n) = A080843(n). - Wolfdieter Lang, Dec 06 2018