1,2

Table of n, a(n) for n=1..81.

E. Angelini, k-chunks sum and division by k, post to the SeqFan list, Mar 22 2013

a(n) = 2 a(n-5) - a(n-10).

G.f.: x*(1 + 2*x + 3*x^2 + 4*x^3 + 5*x^4 + 4*x^5 + 3*x^6 + 2*x^7 + x^8 + 5*x^9)/((1 - x)*(1 + x + x^2 + x^3 + x^4))^2.

a(n)=n unless n=0 (mod 5) in which case a(n)=2n-5.

Cf. A222256-A222260.

Sequence in context: A033081 A032579 A151543 * A242415 A242420 A242419

Adjacent sequences: A222258 A222259 A222260 * A222262 A222263 A222264

nonn

Eric Angelini and M. F. Hasler, Mar 23 2013

approved