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

%I #18 Apr 06 2016 00:11:24

%S 1,3,3,5,12,30,58,128,237,476,975,1956,3899,7798,15534,31270,62262,

%T 124635,248944,497797,995730,1990576,3983767,7969049,15935289,

%U 31870309,63739461,127519282,254994762,510016513,1020092276,2040066241,4080236749

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

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

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

%p read("transforms") :

%p A227616 := proc(n)

%p wt(A003010(n)) ;

%p end proc: # _R. J. Mathar_, Jul 20 2013

%t First@ DigitCount[#, 2] & /@ NestList[#^2 - 2 &, 4, 28] (* _Michael De Vlieger_, Apr 04 2016 *)

%o (PARI) lista(nn) = {a = 4; print1(hammingweight(a), ", "); for (n=1, nn, a = a^2-2; print1(hammingweight(a), ", "););} \\ _Michel Marcus_, Apr 04 2016

%Y Cf. A003010, A227608, A227615.

%K nonn,base

%O 0,2

%A _Olivier de Mouzon_, Jul 17 2013

%E Terms from a(19) on from _Michel Marcus_, Apr 04 2016