A053796 a(n) = (n^2+n) modulo 5.

0, 2, 1, 2, 0, 0, 2, 1, 2, 0, 0, 2, 1, 2, 0, 0, 2, 1, 2, 0, 0, 2, 1, 2, 0, 0, 2, 1, 2, 0, 0, 2, 1, 2, 0, 0, 2, 1, 2, 0, 0, 2, 1, 2, 0, 0, 2, 1, 2, 0, 0, 2, 1, 2, 0, 0, 2, 1, 2, 0, 0, 2, 1, 2, 0, 0, 2, 1, 2, 0, 0, 2, 1, 2, 0, 0, 2, 1, 2, 0, 0, 2, 1, 2, 0, 0, 2, 1, 2, 0, 0, 2, 1, 2, 0, 0, 2, 1, 2, 0, 0, 2, 1, 2, 0

Offset: 0

Author

Stuart M. Ellerstein (ellerstein(AT)aol.com), Mar 27 2000

Keywords

• nonn
• easy

Links

• Index entries for linear recurrences with constant coefficients, signature (0,0,0,0,1).

Crossrefs

Cf. A053793.

Programs

Magma

[(n^2+n) mod 5 : n in [0..100]]; // Wesley Ivan Hurt, Apr 20 2021

Mathematica

Table[Mod[n^2+n,5],{n,0,110}] (* or *) PadRight[{},120,{0,2,1,2,0}] (* Harvey P. Dale, Sep 12 2017 *)

Formula

From Bruno Berselli, Dec 02 2010: (Start)

G.f.: x*(2+x+2*x^2)/(1-x^5);

a(n) = a(n-5) for n > 4. (End)

Extensions

More terms from James Sellers, Apr 08 2000