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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.
2
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
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
KEYWORD
nonn
AUTHOR
Jason Earls, Nov 20 2002
STATUS
approved