A334839 Totients congruent to 2 mod 4 and that have multiplicity 4.

6, 18, 42, 162, 486, 1458, 4422, 6162, 14406, 19182, 22650, 26406, 39366, 77658, 143262, 412806, 527802, 564898, 843642, 981090, 1514130, 2023506, 2453922, 3050262, 3946182, 4042110, 4590306, 5010882, 6931390, 7003962, 7067622, 7195806, 7455630, 9349410, 10696170, 11092230

Offset

1,1

Links

Table of n, a(n) for n=1..36.

Max Alekseyev, PARI/GP Scripts for Miscellaneous Math Problems (see invphi.gp there).

Andre Contiero, and Davi Lima, On the distribution of totients 2 mod. 4, arXiv:1803.01396 [math.NT], 4 Mar 2018.

André Contiero, and Davi Lima, 2-Adic Stratification of Totients, arXiv:2005.05475 [math.NT], 2020.

Example

6 is a term since there are exactly 4 integers x for which phi(x)=6, namely 7, 9, 14, and 18.

Prog

(PARI) isok(m) = ((m%4)==2) && istotient(m) && (#invphi(m)==4);

Crossrefs

Cf. A000010, A002202, A016825, A309502.

Sequence in context: A011930 A330844 A068293 * A272250 A272700 A191101

Adjacent sequences: A334836 A334837 A334838 * A334840 A334841 A334842

Keyword

nonn

Author

Michel Marcus, May 13 2020

Status

approved