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 A188366 Values of c such that (c+9*b)*Prime(n)#-1 is the least prime such that (c+k*b)*Prime(n)#-1 is prime for k=0 to 9 with c+9*b < Prime(n)# , or 0 if no solution. Prime(n)#=n-th primorial 2
 0, 0, 0, 0, 0, 653, 1542, 2035, 2460, 7473, 654, 7394, 7479, 69698, 4646, 25205, 122774, 42953, 444644, 38761, 545933, 83675, 212892, 87123, 106714, 50427, 747235, 1737780, 2371271, 1807313 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,6 COMMENTS b=A188367(n), c*Prime(n)#-1 is the first of an arithmetic progression of 10 primes or more. I use PFGW program from primeform group to generate the primes and my own sieve to find the least sum c+9*b for an arithmetic progression of at least 10 primes, all primes are certified primes by PFGW program. LINKS Table of n, a(n) for n=1..30. EXAMPLE 13#=30030, 30030*653-1=19609589 , 289*30030=8678670 196095899+k*8678670 is prime for k=0 to 9 for n=6 c=653 and b=289 CROSSREFS Cf. A188367. Sequence in context: A198170 A145125 A145202 * A255208 A060520 A250701 Adjacent sequences: A188363 A188364 A188365 * A188367 A188368 A188369 KEYWORD nonn,hard AUTHOR Pierre CAMI, Mar 29 2011 EXTENSIONS More terms from Pierre CAMI STATUS approved

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Last modified August 12 15:11 EDT 2024. Contains 375113 sequences. (Running on oeis4.)