A224532 Largest number k such that phi(k) = A007374(n).

2, 6, 12, 30, 42, 120, 126, 150, 90, 210, 660, 1242, 7938, 2760, 1014, 270, 1470, 810, 3318, 630, 2370, 4830, 7590, 1386, 11220, 1680, 1260, 5082, 13890, 1050, 3570, 33750, 1890, 26082, 14058, 2310, 2730, 5670, 5250, 70140, 12690, 14280, 12474, 3990, 11850

Offset

2,1

Comments

That is, the largest number k such that phi(k) = x, with x being the least number having n solutions. - T. D. Noe, Apr 14 2013

Links

T. D. Noe, Table of n, a(n) for n = 2..1023

D. Bressoud, CNT.m Computational Number Theory Mathematica package.

Mathematica

Needs["CNT`"]; nn = 50; t = Table[0, {nn}]; n = 0; left = nn - 1; While[left > 0, n++; cnt = Length[PhiInverse[n]]; If[cnt <= nn && t[[cnt]] == 0, t[[cnt]] = n; left--]]; Join[{0}, Table[PhiInverse[n][[-1]], {n, Rest[t]}]]

Crossrefs

Cf. A224531.

Sequence in context: A143176 A081375 A024701 * A179674 A038199 A056267

Adjacent sequences: A224529 A224530 A224531 * A224533 A224534 A224535

Keyword

nonn

Author

T. D. Noe, Apr 11 2013

Status

approved