OFFSET
1,2
LINKS
Andrew Howroyd, Table of n, a(n) for n = 1..10000
EXAMPLE
Conjectures from Colin Barker, Oct 14 2019: (Start)
G.f.: x*(1 + 2*x + 4*x^2 + 6*x^3 + x^4 + 4*x^5 + 2*x^6) / ((1 - x)^2*(1 + x)^2*(1 + x^2)^2).
a(n) = 2*a(n-4) - a(n-8) for n>8.
(End)
PROG
(PARI) \\ here S is A026166 as vector.
S(n)={my(a=vector(n)); a[1]=1; for(i=1, 2*n-1, my(h=(i-1)\2); if(!a[i-h], a[i-h]=i, if(i+h<=n, a[i+h]=i))); a}
{[(k + 2)/3 | k<-S(500), k%3==1]} \\ Andrew Howroyd, Oct 15 2019
CROSSREFS
KEYWORD
nonn
AUTHOR
EXTENSIONS
Title corrected by Sean A. Irvine, Sep 20 2019
STATUS
approved