0,4

Digits := 20: tau := evalf( (1+sqrt(5))/2): A005821 := proc(n) option remember; if n <= 1 then n; else A005821(n-2)+floor(tau*A005821(n-1)); fi; end;

Sequence in context: A121485 A098588 A126683 this_sequence A004149 A129986 A110334

Adjacent sequences: A005818 A005819 A005820 this_sequence A005822 A005823 A005824

nonn

N. J. A. Sloane (njas(AT)research.att.com).