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

1,3

Links

Table of n, a(n) for n=1..105.

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

Formula

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

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 *)

Crossrefs

Sum of "digits" of A064743.

Cf. A001222, A064413.

Sequence in context: A319416 A284559 A284583 * A227185 A284579 A167489

Adjacent sequences: A064739 A064740 A064741 * A064743 A064744 A064745

Keyword

nonn

Author

N. J. A. Sloane, Oct 18 2001

Extensions

More terms from Vladeta Jovovic, Oct 20 2001

Status

approved