

A076245


Numbers at which values of A051547 increase.


3



1, 3, 5, 7, 11, 15, 17, 19, 23, 29, 47, 51, 53, 59, 81, 83, 85, 101, 103, 107, 149, 163, 167, 173, 179, 191, 197, 227, 251, 255, 257, 263, 269, 283, 293, 311, 317, 347, 359, 367, 383, 389, 467, 479, 487, 503, 509, 557, 563, 569, 587, 607, 619, 643, 653, 677
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OFFSET

1,2


COMMENTS

Observe that both primes and composites (including 15, 51, 81, 85, and 255) occur.
In totients of consecutive terms some primefactor appears at higher power than in preceding ones: see A076246 and A051451.


LINKS

Michael De Vlieger, Table of n, a(n) for n = 1..13256 (First 1924 terms from Vincenzo Librandi; a(n) <= 10^6.)


MATHEMATICA

With[{s = FoldList[LCM @@ {#1, EulerPhi@ #2} &, Range[700]]}, Map[FirstPosition[s, #][[1]] &, Union@ FoldList[Max, s]]] (* Michael De Vlieger, Dec 09 2018 *)


PROG

(PARI) lista(nn) = {least = 1; print1(1, ", "); for (n=2, nn, nleast = lcm(least, eulerphi(n)); if (nleast > least, print1(n, ", ")); least = nleast; ); } \\ Michel Marcus, Jul 30 2017


CROSSREFS

Cf. A003418, A051451, A051547, A076244.
Sequence in context: A319899 A085493 A139252 * A318953 A172308 A190812
Adjacent sequences: A076242 A076243 A076244 * A076246 A076247 A076248


KEYWORD

nonn


AUTHOR

Labos Elemer, Oct 08 2002


STATUS

approved



