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

1,1

Links

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

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 *)

Crossrefs

Cf. A078142.

Sequence in context: A190495 A271988 A093330 * A025006 A189321 A273072

Adjacent sequences: A071244 A071245 A071246 * A071248 A071249 A071250

Keyword

nonn

Author

Jason Earls, Nov 20 2002

Status

approved