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 A080840 Number of cousin primes < 10^n. 2
 1, 8, 41, 203, 1216, 8144, 58622, 440258, 3424680, 27409999, 224373161, 1870585459 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS The corresponding numbers for twin primes and sexy primes are in A007508 and A080841, the greater of twin primes, cousin primes and sexy primes are in A006512, A046132 and A046117 respectively. LINKS A. Granville, G. Martin, Prime number races, Amer. Math. Monthly vol 113, no 1 (2006) p 1. Eric Weisstein's World of Mathematics, Cousin Primes. PROG (PARI) {c=0; p=5; for(n=1, 9, while(p<10^n, if(isprime(p-4), c++); p=nextprime(p+1)); print1(c, ", "))} CROSSREFS Cf. A007508, A080841, A006512, A046132, A046117. Sequence in context: A273070 A273145 A273176 * A199846 A188180 A026968 Adjacent sequences:  A080837 A080838 A080839 * A080841 A080842 A080843 KEYWORD nonn,more AUTHOR Jason Earls, Mar 28 2003 EXTENSIONS a(8) and a(9) from Klaus Brockhaus, Mar 30 2003 More terms from R. J. Mathar, Aug 05 2007 STATUS approved

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Last modified March 18 19:00 EDT 2018. Contains 300772 sequences. (Running on oeis4.)