0,1

f := proc(n) options remember; if n = 0 then 4 else 1/2*f(n-1)*(f(n-1)+1) fi end

Sequence in context: A018844 A007027 A096423 this_sequence A002290 A104363 A092190

Adjacent sequences: A013586 A013587 A013588 this_sequence A013590 A013591 A013592

nonn

Carl Bellinger (carlb(AT)ctron.com)