A105332 a(n) = n*(n+1)/2 mod 8.

0, 1, 3, 6, 2, 7, 5, 4, 4, 5, 7, 2, 6, 3, 1, 0, 0, 1, 3, 6, 2, 7, 5, 4, 4, 5, 7, 2, 6, 3, 1, 0, 0, 1, 3, 6, 2, 7, 5, 4, 4, 5, 7, 2, 6, 3, 1, 0, 0, 1, 3, 6, 2, 7, 5, 4, 4, 5, 7, 2, 6, 3, 1, 0, 0, 1, 3, 6, 2, 7, 5, 4, 4, 5, 7, 2, 6, 3, 1, 0, 0, 1, 3, 6, 2, 7, 5, 4, 4, 5, 7, 2, 6, 3, 1, 0, 0, 1, 3, 6, 2, 7, 5, 4, 4

Offset: 0

Author

Oscar Takeshita, May 01 2005

Keywords

• nonn
• easy

Comments

Periodic with period length 16. - Ray Chandler, Apr 18 2025

Links

• Index entries for linear recurrences with constant coefficients, signature (1,-1,1,-1,1,-1,1,-1,1,-1,1,-1,1,-1,1).

Crossrefs

Cf. A000217.

See A105198 for further information.

Programs

Mathematica

Mod[Accumulate[Range[0,110]],8] (* Harvey P. Dale, Nov 03 2013 *)

Python

def A105332(n): return (n*(n+1)>>1)&7 # Chai Wah Wu, Apr 17 2025