A076246 Totients of those numbers at which values of A051547 increase: in these consecutive terms new prime powers arise, i.e., which did not occur in neither of preceding terms.

2, 4, 6, 10, 8, 16, 18, 22, 28, 46, 32, 52, 58, 54, 82, 64, 100, 102, 106, 148, 162, 166, 172, 178, 190, 196, 226, 250, 128, 256, 262, 268, 282, 292, 310, 316, 346, 358, 366, 382, 388, 466, 478, 486, 502, 508, 556, 562, 568, 586, 606, 618, 642, 652, 676, 708

Offset

1,1

Links

Table of n, a(n) for n=1..56.

Example

8 = 2*2*2 immediately follows 10 = 2*5; 58 = 2*29 follows 52 = 2*2*13. In both cases, the latter term has a new prime factor (like 29) or an old one at a higher power (like 2*2*2).

Mathematica

s0=1; s1=1; Do[s0=s1; s1=LCM[s1, EulerPhi[n]]; If[ !Equal[s0, s1], Print[n]], {n, 1, 1000}]

Prog

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

Crossrefs

Cf. A003418, A051451, A051547, A076244, A076245.

Sequence in context: A275632 A269360 A243501 * A100426 A213474 A187333

Adjacent sequences: A076243 A076244 A076245 * A076247 A076248 A076249

Keyword

nonn

Author

Labos Elemer, Oct 08 2002

Status

approved