26070

Appears in sequences

• Coordination sequence for A_5 lattice.at n=7A008385
• Number of bipartite graphs with 3 edges on nodes {1..n}.at n=11A053526
• Square array T(n,k) (n >= 1, k >= 0) read by antidiagonals: coordination sequence for root lattice A_n.at n=73A103881
• Pentagonal numbers (A000326) that are the product of 2 palindromes greater than 1.at n=17A115745
• a(n) = n^3 - n^2 - n.at n=30A152015
• Perimeter s/6 (divided by 6) of primitive Pythagorean triangles such that perimeters are Averages of twin prime pairs, q=p+1, a=q^2-p^2, c=q^2+p^2, b=2*p*q, s=a+b+c, s-+1 are primes.at n=18A155176
• Number of integer sequences of length n+1 with sum zero and sum of absolute values 14.at n=4A157056
• a(n) = 841*n - 1.at n=30A158402
• Partial sums of A061262.at n=35A176661
• Numbers n such that 6n and 12n are both the average of twin prime pairs.at n=34A177680
• Array read by antidiagonals: T(m,n) = m*(m+n-1)! + Sum( n <= i <= m+n-2 ) i!at n=25A211369
• Number of (w,x,y) with all terms in {0,...,n} and w <= x + y and x < y.at n=39A212981
• Number of forests with n labeled nodes and 8 trees.at n=3A240685
• Pentagonal numbers that are also Niven numbers.at n=35A242043
• Numbers x such that sigma(x) + sigma(R(x)) = sigma(x + R(x)), where R(x) is the digit reversal of x and sigma(x) is the sum of the divisors of x.at n=25A246487
• Total number of positive integers < 10^n with multiplicative digital root value 5.at n=7A263473
• a(n) = 3*n*(9*n - 1)/2.at n=44A268351
• Numbers k such that 1/phi(x) + 1/phi(y) = 1/phi(k), for some x + y = k and phi(k) is the Euler totient function of k.at n=32A279621
• Number of n X 2 0..1 arrays with no 1 equal to more than two of its horizontal, vertical and antidiagonal neighbors.at n=7A283276
• T(n,k)=Number of nXk 0..1 arrays with no 1 equal to more than two of its horizontal, vertical and antidiagonal neighbors.at n=37A283282