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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A093867 Duplicate of A069549.

Original entry on oeis.org

4, 9, 25, 25, 49, 49, 121, 121, 121, 121, 169, 169, 289, 289, 289, 289, 361, 361, 529
Offset: 1

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Author

Keywords

A069639 Smallest composite k such that phi(k) > k*(1-1/n^2).

Original entry on oeis.org

4, 25, 121, 289, 841, 1369, 2809, 4489, 6889, 10201, 16129, 22201, 29929, 38809, 51529, 66049, 85849, 109561, 134689, 160801, 196249, 237169, 292681, 332929, 398161, 458329, 537289, 619369, 727609, 822649, 935089, 1062961, 1190281
Offset: 1

Views

Author

Benoit Cloitre, Apr 21 2002

Keywords

Crossrefs

Cf. A000010 (phi), A007491, A007918, A069549.

Programs

  • Mathematica
    a[n_] := NextPrime[n^2]^2; Array[a, 40] (* Amiram Eldar, May 08 2025 *)
  • PARI
    a(n) = nextprime(n^2)^2; \\ Amiram Eldar, May 08 2025

Formula

a(n) = nextprime(n^2)^2 = A007918(n^2)^2.
a(n) = A007491(n)^2. - Amiram Eldar, May 08 2025
Showing 1-2 of 2 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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