A127965 Number of bits in A127962(n).

2, 4, 6, 10, 12, 16, 18, 22, 30, 42, 60, 78, 100, 126, 166, 190, 198, 312, 346, 700, 1708, 2616, 3538, 5806, 10500, 10690, 11278, 12390, 14478

Offset

1,1

Comments

Equals A127964(n) + A127963(n).

Links

Table of n, a(n) for n=1..29.

Formula

a(n) = 1 + floor(log_2(A000979(n))) = 1 + floor(log_2(2^A000978(n)+1) - A020857) = A000978(n) - 1. - R. J. Mathar, Feb 01 2008

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, 0]+DigitCount[a[[x]], 10, 1]], {x, 1, Length[a]}]; d (* Artur Jasinski, Feb 09 2007 *)

Crossrefs

Cf. A127962, A127963, A127964, A127961, A000979, A000978, A124400, A126614, A127955, A127956, A127957, A127958, A127936.

Sequence in context: A146886 A006093 A358816 * A117891 A262935 A178539

Adjacent sequences: A127962 A127963 A127964 * A127966 A127967 A127968

Keyword

nonn,base

Author

Artur Jasinski, Feb 09 2007

Extensions

a(22)-a(29) from Vincenzo Librandi, Mar 30 2012

Status

approved