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.

A089523 Primes p such that mu(p+1) = 1; that is, p+1 is squarefree and has an even number of distinct prime factors, where mu is the Moebius function.

Original entry on oeis.org

5, 13, 37, 61, 73, 157, 193, 277, 313, 389, 397, 421, 457, 461, 509, 541, 569, 613, 661, 673, 733, 757, 769, 797, 857, 877, 929, 997, 1093, 1109, 1153, 1201, 1213, 1217, 1229, 1237, 1289, 1301, 1321, 1381, 1409, 1429, 1453, 1481, 1553, 1609, 1621, 1657
Offset: 1

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Author

T. D. Noe, Nov 06 2003

Keywords

Crossrefs

Cf. A089495 (mu(p+1) for prime p), A049098 (primes p with mu(p+1)=0), A078329 (primes p with mu(p+1)=-1).

Programs

  • Magma
    [p: p in PrimesUpTo(2000) | MoebiusMu(p+1) eq 1]; // Vincenzo Librandi, Aug 17 2018
  • Maple
    select(n -> isprime(n) and numtheory:-mobius(n+1)=1, [seq(i,i=1..2000,4)]); # Robert Israel, Aug 16 2018
  • Mathematica
    Select[Prime[Range[300]], MoebiusMu[ #+1]==1&]
  • PARI
    isok(p) = isprime(p) && (moebius(p+1) == 1); \\ Michel Marcus, Aug 16 2018