A233517 Record values in A061026, the smallest number m such that n divides phi(m), where phi is Euler's totient function.

1, 3, 7, 11, 29, 53, 103, 191, 311, 709, 1021, 1091, 1597, 2339, 3547, 5449, 8243, 9337, 13711, 16673, 17579, 18899, 25367, 37217, 62207, 74441, 87869, 94439, 94789, 96353, 114013, 171167, 229981, 397253, 424769, 432781, 496747, 542599, 583397, 673451, 741677

Offset

1,2

Comments

See A233516 for the n that produce these values. After the initial 1, these numbers are prime.

Links

Amiram Eldar, Table of n, a(n) for n = 1..101

Mathematica

t2 = {{1, 1}}; Do[k = 1; While[Mod[EulerPhi[k], n] > 0, k++]; If[k > t2[[-1, 2]], AppendTo[t2, {n, k}]; Print[{n, k}]], {n, 2, 10^3}]; Transpose[t2][[2]]

Prog

(PARI) lista(cmax) = {my(v = vector(cmax), c = 0, k = 1, d, vm = 0); while(c < cmax, d = divisors(eulerphi(k)); for(i = 1, #d, if(d[i] <= cmax && v[d[i]] == 0, c++; v[d[i]] = k)); k++); for(i = 1, cmax, if(v[i] > vm, vm = v[i]; print1(v[i], ", "))); } \\ Amiram Eldar, May 26 2024

Crossrefs

Cf. A061026, A233516.

Sequence in context: A264803 A117790 A014447 * A125879 A238673 A318263

Adjacent sequences: A233514 A233515 A233516 * A233518 A233519 A233520

Keyword

nonn

Author

T. D. Noe, Feb 12 2014

Status

approved