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Search: id:A073457
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| A073457 |
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Numbers n such that to Phi[n]=Pi[n]+2. |
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+0
5
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OFFSET
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1,1
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FORMULA
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Solutions to A000010(x)=A000720(x)+k, where k=+2; finite for any fixed value of k.
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EXAMPLE
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8 primes below 22 = {2,3,5,7,11,13,17,19}; 10 terms in RRS[22]={1,3,5,7,9,13,15,17,19,21}, so 22 is here.
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MATHEMATICA
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Do[s=EulerPhi[n]-PrimePi[n]; If[Equal[s, 2], Print[n]], {n, 1, 10000}]
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CROSSREFS
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Cf. A037228, A037171, A000010, A000720, A073455, A072456.
Sequence in context: A004472 A116025 A020939 this_sequence A047522 A112072 A024902
Adjacent sequences: A073454 A073455 A073456 this_sequence A073458 A073459 A073460
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KEYWORD
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fini,full,nonn
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AUTHOR
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Labos E. (labos(AT)ana.sote.hu), Aug 02 2002
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