68891

Properties

Appears in sequences

• Initial term in sequence of four consecutive primes separated by 3 consecutive differences each <=6 (i.e., when d = 2, 4 or 6) and forming d-pattern=[6,2,4]; short d-string notation of pattern = [624].at n=17A078853
• Primes p such that the differences between the 5 consecutive primes starting with p are (6,2,4,6).at n=5A078958
• a(n) = n*3^(n-1) + (3^n + 1)/2.at n=9A086972
• a(n) is the first term of the sexy prime quadruple a(n), a(n)+6, a(n)+12 and a(n)+18 that becomes a perfect square if the rightmost digit (1) is removed.at n=5A092445
• a(n) is the smallest natural number we cannot obtain from n, n+1, n+2, n+3, n+4, n+5, n+6, n+7 and the operators +, -, *, /, using each number only once.at n=24A143192
• Number of n X n binary arrays symmetric about main diagonal with all ones connected only in a 1000-1000-1111 pattern in any orientation.at n=11A146597
• Primes p such that p-+1, p-+3, p-+5 are not squarefree.at n=14A155145
• a(n) = (7*3^n + 1)/2.at n=9A199109
• Primes of the form 10n^2 + 1.at n=22A201709
• Primes whose trajectories under the map x -> A039951(x) enter the cycle {83, 4871} (conjectured).at n=15A252812
• Rectangular array A read by upward antidiagonals in which the entry in row n and column k is defined by A(n,k) = 5 + 9*A005836(2^(k - 1)*(2 n - 1)), n,k >= 1.at n=43A265159
• Records in the numbers of representations of k^2 as x^2 - x*y + y^2, x > 2*y >= 0, corresponding to the numbers of grid points with squared radius A357302(n)^2 in an angular sector 0 <= phi < Pi/6 of the triangular lattice.at n=25A357303
• Prime numbersat n=6845