1,4

Conjecture. a(n)=1 if n<4, else a(n)=4^[n/4] if n<>4m+3, else a(n)=7*4^([n/4]-1), where [...] denotes the Floor function. (This has been verified up to n=40.)

Cf. A000792, A034893, A094958.

Adjacent sequences: A128936 A128937 A128938 this_sequence A128940 A128941 A128942

Sequence in context: A023958 A137751 A010658 this_sequence A105352 A132200 A110757

nonn

John W. Layman (layman(AT)math.vt.edu), Apr 27 2007