41125

Appears in sequences

• Let c(k) denote the k-th composite number and p(k) the k-th prime number; then a(n) = Sum_{i=n*(n-1)/2+1 .. n*(n+1)/2} c(i) - Sum_{i=1..n} p(i).at n=41A024850
• a(n)= Sum_{d divides n} a(abs(n/d-d)).at n=16A079580
• Numbers n such that 3^n-2^(n-1) is prime.at n=36A095906
• Expansion of (eta(q)^3*eta(q^10)^6)/(eta(q^2)^2*eta(q^5)^7) in powers of q.at n=49A113977
• Eight white queens and one red queen on a 3 X 3 chessboard. G.f.: (1 + x)/(1 - 5*x - 5*x^2).at n=6A180033
• Triangle read by rows, derived from an array of sequences generated from (1 + x)/ (1 - r*x - r*x^2).at n=61A180165
• Number of words of length n on alphabet {1,2,...,n} with no adjacent 1's.at n=6A190526
• Number of (n+2) X 4 binary arrays avoiding patterns 001 and 010 in rows, columns and nw-to-se diagonals.at n=4A202892
• Number of (n+2)X7 binary arrays avoiding patterns 001 and 010 in rows, columns and nw-to-se diagonals.at n=1A202895
• T(n,k)=Number of (n+2)X(k+2) binary arrays avoiding patterns 001 and 010 in rows, columns and nw-to-se diagonals.at n=16A202898
• T(n,k)=Number of (n+2)X(k+2) binary arrays avoiding patterns 001 and 010 in rows, columns and nw-to-se diagonals.at n=19A202898
• Numbers n such that n^6+6 and n^6-6 are prime.at n=6A239429
• Numerators of r(n) := Sum_{k=0..n-1} 1/Product_{j=0..4} (k + j + 1), for n >= 0, with r(0) = 0.at n=35A300298
• Composite k that divides 2^(k-2) + 3^(k-2) + 6^(k-2) - 1.at n=40A318761
• G.f. satisfies A(x) = Sum_{n>=1} A(x^3)^n / A(x^(2*n)), with A(0) = 0 and A'(0) = 1.at n=30A383376