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.

A284440 Smallest number k such that A049559(k) / A187730(k) = n.

Original entry on oeis.org

1, 21, 91, 65, 451, 217, 2059, 1665, 4699, 2101, 24564, 1729, 74023, 9017, 13051, 4097, 60691, 5833, 278693, 20801, 142003, 10649, 47611, 54145, 116251, 47321, 19684, 21953, 338083, 54901, 501643, 53505, 141571, 219641, 169051, 80353, 386059, 515509, 453259, 16401
Offset: 1

Views

Author

Thomas Ordowski and Altug Alkan, Mar 27 2017

Keywords

Comments

For every n, a(n)-1 is not squarefree.

Crossrefs

Cf. A284089.

Programs

  • Mathematica
    a[n_]:= Block[{k=1}, While[GCD[k - 1, EulerPhi[k]]/GCD[CarmichaelLambda[k], k - 1] != n, k++]; k]; Table[a[n], {n, 40}] (* Indranil Ghosh, Mar 27 2017 *)
  • PARI
    a(n)={my(k=1); while(gcd(k - 1, eulerphi(k))/gcd(lcm(znstar(k)[2]),k - 1) != n, k++); k}; \\ Indranil Ghosh, Mar 27 2017