615195

Appears in sequences

• a(n) = Product_{i=1..n} (2^i - 1). Also called 2-factorial numbers.at n=6A005329
• Array of q-factorial numbers n!_q, read by ascending antidiagonals.at n=38A069777
• Denominators of the fixed point a=(a_1,a_2,...) of the transformation x'= fix(x) where fix(x)_n = Sum_{d|n} d x_d, i.e., fix(a)=a.at n=63A153038
• A q-factorial type triangle sequence: t(n,m)=Product[Sum[(m + 1)^i, {i, 0, k - 1}], {k, 1, n}].at n=15A156173
• Array A(n, k) = Product_{j=1..n} ( (k+1)^j - 1 ) with A(n, 0) = n!, read by antidiagonals.at n=34A156540
• Square array T(n, k) = Product_{j=1..n} ( Sum_{i=0..j-1} ((k+1)^2 - (k+1))^i ) with T(n, 0) = n!, read by antidiagonals.at n=34A156881
• Triangle T(n, k, q) = t(n,q)/(t(k,q)*t(n-k,q)), where t(n, k) = Product_{j=1..n} q-Pochhammer(j, k+1, k+1)/(1-(k+1))^j and t(n, 0) = n!, with q = 1, read by rows.at n=22A156950
• Triangle T(n, k, q) = t(n,q)/(t(k,q)*t(n-k,q)), where t(n, k) = Product_{j=1..n} q-Pochhammer(j, k+1, k+1)/(1-(k+1))^j and t(n, 0) = n!, with q = 1, read by rows.at n=26A156950
• a(n) = floor(p/2) * floor(floor(p/2)/2) * floor(floor(floor(p/2)/2)/2) * ... * 1, where p=prime(n).at n=30A163467
• Triangle T(n, k, q) = c(n, q)/(c(k, q)*c(n-k, q)) where c(n,q) = Product_{j=1..n} (q^j -1)^(n-j) and q = 2, read by rows.at n=29A173503
• Triangle T(n, k, q) = c(n, q)/(c(k, q)*c(n-k, q)) where c(n,q) = Product_{j=1..n} (q^j -1)^(n-j) and q = 2, read by rows.at n=34A173503
• Product of cumulative sums of divisors of n.at n=31A197410
• Array: row n shows the coefficients of the characteristic polynomial of the n-th principal submatrix of f(i,j)=(2i-1 if i=j and 1 otherwise) for i>=1 and j>=1 (as in A204131).at n=27A204134
• a(n) = product of numbers k <= sigma(n) such that k = sigma(d) for any divisor d of n where sigma = A000203.at n=31A206031
• a(n) = Product_{d|n} sigma(d) where sigma = A000203.at n=31A206032
• Triangle of numbers S(n,k) (0 <= k <= n) arising in the enumeration of interval orders without duplicated holdings.at n=21A259876
• Triangle read by rows: coefficients eta(n,k) arising from the study of completely transitive graphs on n nodes.at n=27A259970
• Triangle read by rows: coefficients xi(n,k) arising from the study of completely transitive graphs on n nodes.at n=27A259971
• Triangle read by rows: coefficients psi(n,k) arising from the study of completely transitive graphs on n nodes.at n=27A259972
• Triangle read by rows. T(n,k) is the number of flags in an n dimensional vector space over GF(2) that have length exactly k, n >= 0, 0 <= k <= n.at n=27A289546