|
%I #13 Jul 15 2017 11:26:18
%S 0,1,0,2,4,1,6,3,6,5,8,2,5,7,5,4,7,7,10,6,10,9,7,3,7,6,9,8,6,6,9,5,9,
%T 8,9,8,8,11,8,7,11,11,9,10,9,8,9,4,9,8,8,7,10,10,10,9,8,7,11,7,7,10,7,
%U 6,11,10,11,9,11,10,10,9,13,9,13,12,10,9,13,8,13,12,11,12,11,10,12,11,10
%N Number of steps for convergence (to 1 or 3) for the process in A081878.
%e For n = 33 we have 34,17,20,10,5,8,4,2,1 = 9 steps.
%o (PARI) countprp3(n) = { for(x=1,n, c=0; p1 = x; while(p1>1, if(p1%2==0,p1/=2, if(isprime(p1),p1+=3,p1 = p1+1;)); if(p1==3,break); c++; ); print1(c" ") )
%o (MIT Scheme) (define (A081879 n) (cond ((or (= 1 n) (= 3 n)) 0) ((even? n) (1+ (A081879 (/ n 2)))) ((isprime? n) (1+ (A081879 (+ n 3)))) (else (1+ (A081879 (1+ n))))))
%Y Cf. A081878, A006577.
%K easy,nonn
%O 1,4
%A _Cino Hilliard_, Apr 12 2003
%E Edited by _Antti Karttunen_ and _Jud McCranie_, Jun 03 2003
|
