29750

Appears in sequences

• Theta series of A_6 lattice.at n=24A008446
• Expansion of (1-25*x)^(-7/5).at n=3A049395
• a(n) = prime(n)^2 - prime(n+1).at n=39A062235
• Ratio of quadruple Sum of k^2-1 to quadruple sum of k made into an integer sequence: (1/6)*(-1 + n)*(2 + n)*(3 + n)*(7 + n).at n=17A130863
• Number of -7..7 arrays x(0..n-1) of n elements with zero sum and no two consecutive zero elements.at n=4A199529
• Number of -n..n arrays x(0..4) of 5 elements with zero sum and no two consecutive zero elements.at n=6A199532
• Number of 0..2 arrays of length n with each element differing from at least one neighbor by something other than 1, starting with 0.at n=12A221536
• Number of completely uncontrollable graphs on n nodes.at n=7A245545
• 4-step Fibonacci sequence starting with 1,0,1,0.at n=19A251656
• Numbers k such that k!6 + 9 is prime, where k!6 is the sextuple factorial number (A085158 ).at n=33A288154
• Number of nX6 0..1 arrays with every element equal to 0, 1 or 4 horizontally or antidiagonally adjacent elements, with upper left element zero.at n=7A301962
• a(n) = n! * [x^n] Product_{k>=1} 1/(1 - x^k/k!)^n.at n=5A319174
• a(n) = Sum_{k=1..n} 2^k * phi(k), where phi is the Euler totient function A000010.at n=10A324913
• Triangular array, read by rows: T(n,k) = [(x*y)^k] (-1 + (1 + x + 1/x)*(1 + y + 1/y))^n for -n <= k <= n.at n=54A329816
• Triangular array, read by rows: T(n,k) = [(x*y)^k] (-1 + (1 + x + 1/x)*(1 + y + 1/y))^n for -n <= k <= n.at n=58A329816
• Triangle read by rows: T(n,k) is the coefficient of (1+x)^k in the ZZ polynomial of the hexagonal graphene flake O(3,3,n).at n=53A338217
• a(n) = A002070(n) + A036689(n).at n=39A366346
• Numbers k such that k + sopfr(k) is a cube.at n=24A389862
• a(n) is the number of 5 element sets of distinct integer-sided trapezoids each of area less than 3*n^2 whose base angles are 60 degrees that fill a regular hexagon of side n units.at n=35A390763