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 A279515 Number of 0's in the binary expansion of the least common multiple of the first n integers. 1
 0, 0, 1, 1, 2, 2, 2, 5, 6, 6, 6, 9, 9, 7, 7, 7, 8, 12, 12, 16, 16, 16, 16, 19, 19, 14, 14, 19, 19, 25, 25, 25, 26, 26, 26, 26, 26, 25, 25, 25, 25, 33, 33, 32, 32, 32, 32, 29, 29, 32, 32, 32, 32, 35, 35, 35, 35, 35, 35, 46, 46, 45 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,5 LINKS Indranil Ghosh, Table of n, a(n) for n = 0..10000 EXAMPLE For n = 10, the LCM of all the numbers from 1 to 10 is 2520 = 100111011000_2, which has a total of 6 0's, so a(10) = 6. MATHEMATICA Map[DigitCount[#, 2, 0] &, {1}~Join~Table[LCM @@ Range@ n, {n, 61}]] (* Michael De Vlieger, Dec 16 2016 *) PROG (Python) def gcd(a, b):     while b:         a, b = b, a % b     return a def lcm(a, b):     return a * b // gcd(a, b) def c(*ar):     return reduce(lcm, ar) def a(n):     if n==0:         return 0     x=bin(c(*range(1, n+1)))[2:]     return x.count("0") for i in range(0, 10001):     print str(i)+" "+str(a(i)) (PARI) a(n) = my(lcmn = lcm(vector(n, k, k))); #binary(lcmn) - hammingweight(lcmn); \\ Michel Marcus, Dec 23 2016 CROSSREFS Cf. A003418, A279506. Sequence in context: A097006 A033306 A136347 * A260338 A023569 A263373 Adjacent sequences:  A279512 A279513 A279514 * A279516 A279517 A279518 KEYWORD nonn,base AUTHOR Indranil Ghosh, Dec 13 2016 STATUS approved

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