1,1

A143201(a(n)) = 7;

A020639(a(n))in A023201 and A006530(a(n)) in A046117;

subsequence of A007774: A001221(a(n))=2; A111192 is a

subsequence.

Eric Weisstein's World of Mathematics, Sexy Primes

Index entries for primes, gaps between

a(1) = 55 = 5 * 11 = A023201(1) * A046117(1);

a(2) = 91 = 7 * 13 = A023201(2) * A046117(2);

a(3) = 187 = 11 * 17 = A023201(3) * A046117(3);

a(4) = 247 = 13 * 19 = A023201(4) * A046117(4);

a(5) = 275 = 5^2 * 11 = A023201(1)^2 * A046117(1);

a(6) = 391 = 17 * 23 = A023201(5) * A046117(5);

a(7) = 605 = 5 * 11^2 = A023201(1) * A046117(1)^2;

a(8) = 637 = 7^2 * 13 = A023201(2)^2 * A046117(2);

a(9) = 667 = 23 * 29 = A023201(6) * A046117(6);

a(10) = 1147 = 31 * 37 = A023201(7) * A046117(7).

Sequence in context: A039533 A157484 A027865 this_sequence A111192 A063873 A063131

Adjacent sequences: A143202 A143203 A143204 this_sequence A143206 A143207 A143208

nonn

Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Jul 30 2008