A064742 Total number of primes (with multiplicity) dividing A064413(n).

0, 1, 2, 2, 1, 2, 3, 3, 2, 1, 2, 3, 2, 1, 2, 4, 4, 3, 2, 1, 2, 3, 3, 2, 2, 3, 2, 1, 2, 4, 5, 2, 1, 2, 3, 2, 1, 2, 3, 4, 3, 2, 1, 2, 5, 3, 3, 4, 4, 2, 3, 4, 2, 2, 3, 2, 1, 2, 3, 2, 1, 2, 5, 6, 3, 2, 1, 2, 3, 3, 3, 5, 2, 1, 2, 4, 4, 2, 4, 2, 1, 2, 4, 2, 2, 4, 3, 2, 1, 2, 6, 3, 2, 4, 3, 3, 3, 5, 2, 1, 2, 3, 3, 5, 3

Offset: 1

Author

N. J. A. Sloane, Oct 18 2001

Keywords

• nonn

Links

• J. C. Lagarias, E. M. Rains and N. J. A. Sloane, The EKG sequence, arXiv:math/0204011 [math.NT], 2002.
• J. C. Lagarias, E. M. Rains and N. J. A. Sloane, The EKG sequence, Exper. Math. 11 (2002), 437-446.
• Index entries for sequences related to EKG sequence

Crossrefs

Sum of "digits" of A064743.

Cf. A001222, A064413.

Programs

Mathematica

terms = 105;
ekg[s_] := Block[{m = s[[-1]], k = 3}, While[MemberQ[s, k] || GCD[m, k] == 1, k++]; Append[s, k]];
EKG = Nest[ekg, {1, 2}, terms-2];
PrimeOmega /@ EKG (* Jean-François Alcover, Sep 02 2018, after Robert G. Wilson v in A064413 *)

Formula

a(n) = A001222(A064413(n)). - Michel Marcus, Aug 21 2023

Extensions

More terms from Vladeta Jovovic, Oct 20 2001