A362230 Unitary sparsely totient numbers: numbers k such that m > k implies uphi(m) > uphi(k), where uphi is the unitary totient function (A047994).

2, 6, 10, 14, 30, 42, 66, 78, 102, 114, 138, 210, 222, 330, 390, 462, 510, 570, 690, 714, 798, 870, 930, 966, 1110, 1230, 1290, 1302, 1410, 1470, 1590, 1770, 2310, 2730, 3570, 3990, 4290, 4830, 5610, 6090, 6510, 6630, 7770, 8610, 9030, 9870, 10230, 11130, 11310

Offset: 1

Author

Amiram Eldar, Apr 12 2023

Keywords

• nonn

Links

• Amiram Eldar, Table of n, a(n) for n = 1..300

Crossrefs

The unitary version of A036913.

Record values of A362229.

Cf. A047994, A361966, A362231.

Programs

Mathematica

s[n_] := If[(inv = invUPhi[n]) == {}, 0, Max[inv]]; seq[kmax_] := Module[{v = {}, s1, sm = 0}, Do[s1 = s[k]; If[s1 > sm, sm = s1; AppendTo[v, s1]], {k, 1, kmax}]; v]; seq[3000] (* using the function invUPhi from A361966 *)