OFFSET
1,1
FORMULA
MATHEMATICA
b = {}; Do[c = 1 + Sum[2^(2n - 1), {n, 1, x}]; If[PrimeQ[c], AppendTo[b, c]], {x, 0, 1000}]; a = {}; Do[AppendTo[a, FromDigits[IntegerDigits[b[[x]], 2]]], {x, 1, Length[b]}]; d = {}; Do[AppendTo[d, DigitCount[a[[x]], 10, 1]], {x, 1, Length[a]}]; d (* Artur Jasinski, Feb 09 2007 *)
DigitCount[#, 2, 1]& /@ Select[Table[(2^p + 1)/3, {p, Prime[Range[300]]}], PrimeQ] (* Amiram Eldar, Jul 23 2023 *)
CROSSREFS
KEYWORD
nonn,base,more
AUTHOR
Artur Jasinski, Feb 09 2007
EXTENSIONS
a(22)-a(29) from Vincenzo Librandi, Mar 31 2012
a(30)-a(41) from Amiram Eldar, Jul 23 2023
STATUS
approved