17947

Appears in sequences

• Products of 2 successive primes.at n=31A006094
• "DFK" (bracelet, size, unlabeled) transform of 1,2,3,4...at n=18A032216
• Numbers n such that 73*2^n-1 is prime.at n=10A050562
• Number of primitive (aperiodic) palindromic structures using a maximum of five different symbols.at n=18A056479
• Sums of members of groups in A076062.at n=32A076060
• Integer part of n#/(p-7)#, where p=preceding prime to n.at n=29A102792
• (1/8)*number of equilateral triangles that can be formed from the points of an (n+1)X(n+1)X(n+1) lattice cube.at n=10A103501
• Product of the n-th sexy prime pair.at n=19A111192
• Index of first occurrence of the first n digits of Pi in the decimal expansion of e.at n=3A115234
• Number of permutations of length n which avoid the patterns 1243, 2341, 4132.at n=9A116740
• Positions of harmonic numbers in the EKG sequence.at n=12A140804
• Numbers having exactly two distinct prime factors p, q with q = p+6.at n=38A143205
• Numbers n such that exactly two positive d in the range d <= n/2 exist which divide binomial(n-d-1, d-1) and which are not coprime to n.at n=29A178098
• Semiprimes which are the sum of three distinct positive cubes in two or more distinct ways.at n=23A180089
• Product of adjacent primes with a gap of 6.at n=7A210477
• Number of lower triangular n X n arrays colored with integers 0 upwards introduced in row major order, with no element equal to any diagonal or antidiagonal neighbor, and containing the value n(n+1)/2-6.at n=3A211962
• T(n,k)=Number of lower triangular n X n arrays colored with integers 0 upwards introduced in row major order, with no element equal to any diagonal or antidiagonal neighbor, and containing the value n(n+1)/2-k-1.at n=31A211963
• a(n) = A050376(n)*A050376(n+1) where A050376(n) is the n-th number of the form p^(2^k) with p is prime and k >= 0.at n=38A240521
• Semiprimes whose prime factors are of equal binary length and which differ from each other in exactly two bit positions.at n=42A261074
• Sequence of pairwise relatively prime numbers of class P_3 (see comment).at n=16A275246