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A373938
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Number of k in the range s(1), ..., s(n-1) such that gcd(k, s(n)) > 1, where s = A089088.
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1
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0, 0, 1, 2, 1, 3, 2, 4, 1, 7, 6, 1, 6, 7, 11, 11, 8, 10, 1, 15, 4, 12, 1, 8, 15, 21, 15, 12, 16, 1, 10, 23, 18, 1, 14, 23, 29, 23, 20, 22, 1, 31, 6, 29, 18, 27, 35, 14, 31, 20, 28, 1, 43, 30, 1, 26, 31, 16, 45, 35, 24, 45, 47, 36, 1, 34, 39, 16, 53, 47, 26, 40, 1, 59, 20, 42, 1, 30, 47, 65, 18
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OFFSET
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0,4
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COMMENTS
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In the terms studied a(n) = 1 if s(n) is 4 or a prime.
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LINKS
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EXAMPLE
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MATHEMATICA
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nn = 120; s[0] = 1; s[1] = p = 2; s[2] = i = 4; s[3] = j = 6;
Do[If[PrimeQ[j/2],
k = Prime[p++],
k = If[PrimeQ[j], i, j] + 1; While[PrimeQ[k], k++]];
Set[{s[n], i, j}, {k, j, k}], {n, 4, nn}];
s = Array[s, nn];
{0}~Join~Table[Function[{m, w}, Count[w, _?(! CoprimeQ[#, m[[1]]] &)]] @@
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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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