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 A127963 Number of 1's in A127962(n). 3
 2, 3, 4, 6, 7, 9, 10, 12, 16, 22, 31, 40, 51, 64, 84, 96, 100, 157, 174, 351, 855, 1309, 1770, 2904, 5251, 5346, 5640, 6196, 7240, 21369, 41670, 47685, 58620, 63516, 69469, 70540, 133509, 134994, 187161, 493096, 2015700 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Table of n, a(n) for n=1..41. FORMULA a(n) = A000120(A000979(n)). - Michel Marcus, Nov 07 2013 a(n) = A007953(A127962(n)). - Amiram Eldar, Jul 23 2023 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 Cf. A000120, A000978, A000979, A007953, A124400, A126614, A127936, A127955, A127956, A127957, A127958, A127961, A127962. Sequence in context: A111333 A047701 A164528 * A031403 A189578 A190859 Adjacent sequences: A127960 A127961 A127962 * A127964 A127965 A127966 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

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Last modified October 1 22:38 EDT 2023. Contains 365828 sequences. (Running on oeis4.)