A167348 Let a(n) be the n-th term of the sequence. Let m = primorial(a(n)); m is the minimum positive integer such that m/phi(m) >= n.
2, 2, 3, 7, 13, 23, 43, 79, 149, 257, 461, 821, 1451, 2549, 4483, 7879, 13859, 24247, 42683, 75037, 131707, 230773, 405401, 710569, 1246379, 2185021, 3831913, 6720059, 11781551, 20657677, 36221753, 63503639, 111333529, 195199289
Offset: 1
Keywords
Examples
primorial(7) = 210; 210/phi(210) = 210/48 >= 4;
Crossrefs
Cf. A091440.
Programs
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PARI
al(lim) = local(mm,n,m); mm=3; n=2; m=1; forprime(x=3,lim, n*=x; m*= (x-1); if (n\m >= mm, print1(x","); mm++)); /* This will generate all terms of this sequence from the 3rd onward, up to lim. The computation slows down for large values because of the size of the internal values. */
Extensions
Edited and extended by Franklin T. Adams-Watters and N. J. A. Sloane, Aug 29 2009
Comments