A227616 Number of bits set to 1 in the binary representation of the n-th term of the Lucas-Lehmer sequence (A003010).

1, 3, 3, 5, 12, 30, 58, 128, 237, 476, 975, 1956, 3899, 7798, 15534, 31270, 62262, 124635, 248944, 497797, 995730, 1990576, 3983767, 7969049, 15935289, 31870309, 63739461, 127519282, 254994762, 510016513, 1020092276, 2040066241, 4080236749

Offset: 0

Author

Olivier de Mouzon, Jul 17 2013

Keywords

• nonn
• base

Examples

			For n = 2, A003010(2) = 11000010 (in binary), so a(2) = 3.
		

Crossrefs

Cf. A003010, A227608, A227615.

Programs

Maple

read("transforms") :
A227616 := proc(n)
    wt(A003010(n)) ;
end proc: # R. J. Mathar, Jul 20 2013

Mathematica

First@ DigitCount[#, 2] & /@ NestList[#^2 - 2 &, 4, 28] (* Michael De Vlieger, Apr 04 2016 *)

PARI

lista(nn) = {a = 4; print1(hammingweight(a), ", "); for (n=1, nn, a = a^2-2; print1(hammingweight(a), ", "););} \\ Michel Marcus, Apr 04 2016

Formula

a(n) = A000120(A003010(n)).

Extensions

Terms from a(19) on from Michel Marcus, Apr 04 2016