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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A292283 Numbers n such that f(g(n)) - g(f(n)) = n where f = A001065 and g = A051953.

Original entry on oeis.org

9358, 209662, 2900878, 199550158
Offset: 1

Views

Author

Altug Alkan, Sep 13 2017

Keywords

Comments

If 2*p is in this sequence for a prime p, then p + 2 is the arithmetic mean of sigma(p + 1) and phi(p + 3). For the first four terms, primes p such that 2*p is in this sequence are 4679, 104831, 1450439, 99775079.
a(5) > 3*10^10. - Giovanni Resta, Sep 15 2017

Examples

			9358 is a term because A001065(A051953(9358)) - A051953(A001065(9358)) = 11700 - 2342 = 9358.

Crossrefs

Cf. A001065, A051953, A291869, A292208.

Programs

  • PARI
    a001065(n) = sigma(n)-n;
a051953(n) = n-eulerphi(n);
isok(n) = a001065(a051953(n))-a051953(a001065(n))==n;
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