OFFSET
0,3
LINKS
N. J. A. Sloane, Table of n, a(n) for n = 0..10000
MAPLE
M:=1000;
a:=Array(0..M, 0); # A108618 (with different offset)
b:=Array(0..M, 0); # A108619 (with different offset)
c:=Array(0..M, 0); # A272693
f:=n->sign(n)*(n mod 2);
a[0]:=0; b[0]:=0; c[0]:=0;
for n from 1 to M do
b[n]:=1+(a[n-1]+b[n-1])/2;
a[n]:=1+c[n-1]+f(c[n-1])+3*f(b[n]-1);
c[n]:=(a[n]-3*b[n])/2;
od:
[seq(a[n], n=0..M)];
[seq(b[n], n=0..M)];
[seq(c[n], n=0..M)];
CROSSREFS
KEYWORD
sign
AUTHOR
N. J. A. Sloane, Jun 07 2016
STATUS
approved