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Search: id:A073319
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| A073319 |
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A073318(n)=2^g[n]-Sum[C(g(n),g(j))] is positive, where g is EulerPhi and j=0...n. |
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+0
1
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| 19, 23, 29, 31, 37, 43, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 121, 127, 131, 137, 139, 149, 151, 157, 163, 167, 173, 179, 181, 191, 193, 197, 199, 211, 223, 227, 229, 233, 239, 241, 251, 257, 263, 269, 271, 277, 281, 283, 289, 293
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OFFSET
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1,1
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FORMULA
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Solutions to A066781(x)-A073317(x)>0
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EXAMPLE
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Several values are composites:121,289,437,529,...,961,989. Primes like 2,...,17,41 are not here.
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MATHEMATICA
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g[x_] := EulerPhi[x] Do[s=2^g[n]-Apply[Plus, Table[Binomial[g[n], g[j]], {j, 0, n}]]; If[Sign[s]==1&&!PrimeQ[n], k=k+1; Print[{k, n, PrimeQ[n]}]], {n, 1, 1000}]
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CROSSREFS
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Cf. A066781, A073317, A073318.
Adjacent sequences: A073316 A073317 A073318 this_sequence A073320 A073321 A073322
Sequence in context: A095222 A070299 A100460 this_sequence A120640 A076056 A068654
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KEYWORD
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nonn
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AUTHOR
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Labos E. (labos(AT)ana.sote.hu), Jul 26 2002
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