from math import log def IsPrime(n): if n < 2: return 0 elif n == 2 or n == 3: return 1 elif n%2 == 0 or n%3 == 0: return 0 else: d, dd = 5, 2 while d*d <= n and n%d != 0: d, dd = d+dd, 6-dd if d*d <= n: return 0 else: return 1 def nextp(p): m = p%6 if m == 1: d = 4 else: # m == 5 d = 2 ptry, d = p+d, 6-d while not IsPrime(ptry): ptry, d = ptry+d, 6-d return ptry file = open("A166113.txt","r") n = 0 print("n : A256891 A343194 A343195 'diameter' A270305 'normalized mean gap'") while 1: n = n+1 p5 = int(file.readline()) p6 = nextp(p5) p7 = nextp(p6) p8 = nextp(p7) p9 = nextp(p8) if p6-p5 == p9-p8: # type 1 b, c = p6-p5, p7-p6 st = "type 1" elif p6-p5 != p9-p8: # type 2 b, c = p7-p5, p6-p7 st = "type 2" else: print("error") a, d, s = p5-3*b-c, 6*b+2*c, 3*p5 p1,p2,p3,p4,p5,p6,p7,p8,p9=a,a+b,a+2*b,a+2*b+c,a+3*b+c,a+4*b+c,a+4*b+2*c,a+5*b+2*c,a+6*b+2*c print(n,":",a,b,c,d,s,d/(8*log(p1)))