A259439 a(n) = A143482(n)/n.

1, 1, 1, 1, 1, 2, 1, 2, 3, 5, 3, 6, 3, 4, 3, 4, 3, 6, 3, 5, 5, 7, 5, 12, 5, 11, 9, 14, 7, 23, 7, 13, 11, 16, 13, 24, 11, 22, 17, 25, 11, 36, 13, 29, 25, 29, 17, 47, 19, 40, 27, 37, 19, 53, 25, 43, 29, 37, 19, 67, 19, 37, 31, 37, 25, 61, 23, 47, 37, 67, 29, 83

Offset

1,6

Comments

a(1) = 1. For n > 1, a(n) is the least positive k such that phi(k*n) >= phi(a(n-1)*(n-1)), where phi(m) is A000010(m).

Links

Peter Kagey, Table of n, a(n) for n = 1..10000

Mathematica

a = t = {1}; lim = 72; Do[k = 1; While[EulerPhi[k n] < t[[n - 1]], k++]; AppendTo[a, k]; AppendTo[t, EulerPhi[k n]], {n, 2, lim}]; a (* Michael De Vlieger, Sep 22 2015 *)

Prog

(PARI) lista(nn) = {print1(a=1, ", "); for (n=2, nn, k = 1; phia = eulerphi(a); while(eulerphi(k*n) < phia, k++); a = k*n; print1(k, ", "); ); } \\ Michel Marcus, Oct 05 2015

Crossrefs

Cf. A143482.

Sequence in context: A054502 A371335 A059346 * A274491 A076492 A127462

Adjacent sequences: A259436 A259437 A259438 * A259440 A259441 A259442

Keyword

nonn

Author

Peter Kagey, Sep 03 2015

Status

approved