OFFSET
1,2
FORMULA
a(n) = A139286(n)/4 - 1.
a(n) = A139290(n) - 1. - Omar E. Pol, Mar 10 2020
MATHEMATICA
(2^(2#-1))/4-1&/@Prime[Range[20]] (* Harvey P. Dale, May 08 2011 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Omar E. Pol, Apr 13 2008
EXTENSIONS
Edited by Max Alekseyev, May 03 2009, Mar 07 2020
STATUS
approved