OFFSET
1,2
FORMULA
a(n)=floor(r*n-(4*r-1)/(r+1)) where r= (1/2) *(3+sqrt(13))
MATHEMATICA
Module[{seq={0}, n=2}, Do[If[MemberQ[seq, n], AppendTo[seq, Last[seq]+4], AppendTo[seq, Last[seq]+3]]; n++, {60}]; seq] (* Harvey P. Dale, Nov 20 2012 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Benoit Cloitre, Apr 11 2003
STATUS
approved