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.

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

Author

Jason Earls, Nov 20 2002

Keywords

• nonn

Comments

Are there infinitely many k-tuples in A078142?

Links

• Amiram Eldar, Table of n, a(n) for n = 1..5000

Crossrefs

Cf. A071247, A078142.

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 *)