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.

Showing 1-1 of 1 results.

A073938 Numbers n such that A078142(n) = A078142(n+1) = A078142(n+2), where A078142(n) is the sum of the differences of the distinct prime factors p of n and the next square larger than p.

Original entry on oeis.org

153, 3009, 3288, 5170, 5364, 11186, 11295, 11395, 12874, 13545, 16288, 17892, 27760, 28118, 34187, 38907, 47650, 55282, 63455, 64972, 65290, 95886, 104718, 106793, 110944, 155573, 163964, 169644, 172081, 187164, 202607, 203255, 204609
Offset: 1

Views

Author

Jason Earls, Nov 20 2002

Keywords

Comments

Are there infinitely many k-tuples in A078142?

Crossrefs

Programs

  • Mathematica
    s[n_] := Total[Ceiling[Sqrt[(p = FactorInteger[n][[;; , 1]])]]^2 - p]; s1 = s2 = 0; seq = {}; Do[s3 = s[n]; If[s1 == s2 == s3, AppendTo[seq, n - 2]]; s1 = s2; s2 = s3, {n, 3, 2*10^5}]; seq (* Amiram Eldar, Dec 08 2019 *)
Showing 1-1 of 1 results.