22491

Appears in sequences

• a(n) = n^2*(5*n-3)/2.at n=21A006597
• Expansion of 1/((1-2x)(1-4x)(1-5x)(1-8x)).at n=4A025960
• a(n) = T(n,2n-4), T given by A027052.at n=10A027060
• If p(k) is the k-th prime, then the n-th set of 3 consecutive cousin prime pairs starts at p(a(n)).at n=34A095970
• Natural numbers that can be factored into the product of three positive integers whose minimal sum is achieved in more than one way.at n=26A112536
• First trisection of A028560.at n=49A147651
• Exponential Riordan array [exp(sinh(x)*exp(x)), sinh(x)*exp(x)].at n=31A154602
• Totally multiplicative sequence with a(p) = 10p+1 for prime p.at n=19A166668
• a(n) = (7*n^4 + 5*n^2)/12.at n=13A185505
• Number of -2..2 arrays x(i) of n+1 elements i=1..n+1 with set{t,u,v in 0,1}((x[i+t]+x[j+u]+x[k+v])*(-1)^(t+u+v)) having one, three, four, five, six or seven distinct values for every i,j,k<=n.at n=6A211587
• Number of nX2 0..2 arrays with no more than floor(nX2/2) elements equal to at least one horizontal or vertical neighbor, with new values introduced in row major 0..2 order.at n=5A222849
• T(n,k)=Number of nXk 0..2 arrays with no more than floor(nXk/2) elements equal to at least one horizontal or vertical neighbor, with new values introduced in row major 0..2 order.at n=22A222853
• T(n,k)=Number of nXk 0..2 arrays with no more than floor(nXk/2) elements equal to at least one horizontal or vertical neighbor, with new values introduced in row major 0..2 order.at n=26A222853
• T(n,k)=Number of nXk 0..2 arrays with no more than floor(nXk/2) elements equal to at least one horizontal, diagonal or antidiagonal neighbor, with new values introduced in row major 0..2 order.at n=26A223000
• Matrix inverse of triangle A227342.at n=40A227343
• Expansion of e.g.f. exp( x/3 * (exp(3 * x) - 1) ).at n=7A354312
• a(n) = A000265(A263931(n)).at n=26A356637
• Composite numbers k, not squarefree semiprimes, such that k' is a sum of distinct primorial numbers, where k' stands for the arithmetic derivative of k, A003415.at n=53A369642
• Expansion of e.g.f. f(x)^3 * exp(f(x)) / 6, where f(x) = (exp(2*x) - 1)/2.at n=7A383205