0,2

A008936 := proc(n) option remember; if n <= 3 then 2^n else 2*A008936(n-1)-2^(n-4); fi; end;

a(n)=2^n-2^(n-4)*max(n-3, 0)

Sequence in context: A114833 A065617 A062065 this_sequence A073769 A008937 A128805

Adjacent sequences: A008933 A008934 A008935 this_sequence A008937 A008938 A008939

sign

njas, Alejandro Teruel (teruel(AT)usb.ve)

Better description from Michael Somos, Jan 12 2000.