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A290572
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Least number that is the start of a gap of size n between numbers that are either prime or twice a prime (A001751).
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1
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2, 11, 7, 67, 53, 47, 514, 401, 317, 181, 467, 526, 1069, 2819, 1262, 3142, 1382, 1913, 1327, 4178, 2477, 9697, 8123, 8329, 3274, 11213, 21031, 5119, 16382, 13063, 20446, 44417, 22193, 37747, 12854, 46957, 35617, 63863, 48679, 20809, 76166, 39251, 110359, 59282, 136898, 212923, 143006
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OFFSET
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1,1
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COMMENTS
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Numbers that are less than any later number are recorded in A290488.
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LINKS
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EXAMPLE
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a(1) is 2 since 3 - 2 = 1;
a(2) is 11 since 13 - 11 = 2;
a(3) is 7 since 10 - 7 = 3;
a(4) is 67 since 71 - 67 = 4; etc.
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MATHEMATICA
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nxt[n_] := Block[{k = n +1}, While[ !PrimeQ[k] && !PrimeQ[k/2], k++]; k]; p = 2; q = 3; t[_] = 0; While[p < 215000, d = q - p; If[ t[d] == 0, t[d] = p]; p = q; q = nxt@ q]; t@# & /@ Range@ 47
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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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