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A202821
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Position of 6^n among 3-smooth numbers A003586.
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4
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1, 5, 14, 26, 43, 64, 89, 119, 153, 191, 233, 279, 330, 385, 444, 507, 575, 646, 722, 802, 886, 975, 1067, 1164, 1266, 1371, 1481, 1595, 1713, 1835, 1961, 2092, 2227, 2366, 2509, 2657, 2809, 2965, 3125, 3289, 3458, 3630, 3807, 3989, 4174, 4364, 4558, 4756
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OFFSET
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0,2
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LINKS
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FORMULA
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a(n) ~ (log(6))^2/(log(3)*log(4))*n^2 = 2.1079...*n^2.
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EXAMPLE
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a(0) = 1 because A003586(1) = 6^0 = 1.
a(1) = 5 because A003586(5) = 6^1 = 6.
a(2) = 14 because A003586(14) = 6^2 = 36.
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MATHEMATICA
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a[n_] := Sum[Floor[Log[3, 6^n/2^i]] + 1, {i, 0, Log2[6^n]}]; Array[a, 50, 0] (* Amiram Eldar, Jul 15 2023 *)
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PROG
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(Python) # uses imports/function in A372401
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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