A071247 Numbers n such that A078142(n) = A078142(n+1), where A078142(n) is the sum of the differences of the distinct prime factors p of n and the next square larger than p.

7, 12, 19, 29, 86, 96, 99, 121, 132, 138, 153, 154, 164, 183, 192, 220, 230, 234, 251, 274, 280, 286, 353, 390, 444, 455, 476, 484, 539, 589, 651, 675, 704, 730, 774, 785, 813, 850, 867, 944, 965, 1069, 1152, 1216, 1238, 1250, 1266, 1280, 1299, 1308, 1333

Offset: 1

Author

Jason Earls, Nov 20 2002

Keywords

• nonn

Links

• Amiram Eldar, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A078142.

Programs

Mathematica

s[n_] := Total[Ceiling[Sqrt[(p = FactorInteger[n][[;;,1]])]]^2 - p]; s0 = 0; seq = {}; Do[s2 = s[n]; If[s1 == s2, AppendTo[seq, n - 1]]; s1 = s2, {n, 2, 1334}]; seq (* Amiram Eldar, Dec 05 2019 *)