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1, 12, 40, 56, 144, 176, 208, 240, 544, 608, 672, 736, 800, 864, 928, 992, 2112, 2240, 2368, 2496, 2624, 2752, 2880, 3008, 3136, 3264, 3392, 3520, 3648, 3776, 3904, 4032, 8320, 8576, 8832, 9088, 9344, 9600, 9856, 10112, 10368, 10624, 10880, 11136, 11392, 11648, 11904
(list;
graph;
refs;
listen;
history;
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internal format)
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OFFSET
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1,2
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COMMENTS
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If k is a term of this sequence then k*2^m is a term of A116882 for any m >= 0.
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LINKS
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FORMULA
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a(n) = (2*n-1)*2^A070941(n-1), for n > 1.
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MATHEMATICA
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q[n_] := 2^(2*IntegerExponent[n, 2]) >= n; Join[{1}, Select[Range[2, 12000, 2], q[#] && !q[#/2] &]]
(* or *)
a[1] = 1; a[n_] := (2*n - 1)*2^IntegerLength[2*n - 1, 2]; Array[a, 100]
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PROG
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(PARI) a(n) = if(n == 1, 1, (2*n - 1)*2^length(binary(2*n - 1)));
(Python)
def A363121(n): return (m:=2*n-1)<<m.bit_length() if n>1 else 1 # Chai Wah Wu, May 17 2023
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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STATUS
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approved
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