cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

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A168158 Indices n for which A168157(n) is prime.

Original entry on oeis.org

7, 10, 11, 12, 15, 18, 29, 35, 45, 49, 51, 55, 58, 65, 80, 82, 84, 89, 93, 95, 114, 119, 128, 130, 140, 142, 149, 155, 157, 160, 166, 171, 173, 175, 191, 192, 209, 210, 218, 235, 240, 251, 262, 263, 269, 280, 305, 315, 321, 324, 328, 337, 341, 344, 345, 363, 372
Offset: 1

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Author

M. F. Hasler, Nov 21 2009

Keywords

Comments

If n=primepi(2^k-1) is in this sequence, then A158671(k) is prime. This happens for k=5, 6, 18,... corresponding to n=11, 18, 23000,... (cf. link).

Links

Programs

  • PARI
    s=0; for(n=1,999, isprime(n*#(b=binary(prime(n)))-s+=norml2(b)) & print1(n", "))
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