81675

Appears in sequences

• Number of walks on square lattice. Column y=3 of A052174.at n=8A005561
• Composite numbers k+1 such that k*phi(k+1) is a perfect square.at n=39A069068
• a(n) = n*(2*n+1)^2.at n=27A084367
• Numbers k such that both k and k+1 are abundant.at n=20A096399
• Numbers k such that both sigma(k) >= 2*k-1 and sigma(k+1) >= 2*(k+1)-1.at n=22A103289
• Triangle, read by rows, of Stirling numbers of second kind, S2(n,k), multiplied by k^k, for n >= 1, 1<=k<=n.at n=38A105197
• a(n) = (n+1)^2*(n+2)^2*(n+3)^2*(n+4)/144.at n=8A108647
• Triangular array of generalized Narayana numbers: T(n, k) = 4*binomial(n+1, k+3)*binomial(n+1, k-1)/(n+1).at n=40A145598
• a(n) is the number of walks from (0,0) to (0,3) that remain in the upper half-plane y >= 0 using 2*n +1 unit steps either up (U), down (D), left (L) or right (R).at n=4A145602
• A symmetrical triangle based on Stirling numbers of the second kind :q=3;t(n,m,q)=If[m == 0 Or m == n, 1, If[Floor[n/2] greater than or equal to m, StirlingS2[ n, m]*q^m, StirlingS2[n, n - m]*q^(n - m)]].at n=48A174546
• A symmetrical triangle based on Stirling numbers of the second kind :q=3;t(n,m,q)=If[m == 0 Or m == n, 1, If[Floor[n/2] greater than or equal to m, StirlingS2[ n, m]*q^m, StirlingS2[n, n - m]*q^(n - m)]].at n=51A174546
• Numbers of the form p^3*q^2*r^2 where p, q, and r are distinct primes.at n=33A179695
• Positive integers, c, such that there are more than two solutions to the equation a^2 + b^3 = c^4, with a, b > 0.at n=45A242381
• Triangle used for the integral of odd powers of the sine and cosine functions.at n=18A254932
• Numbers k such that both k and k+1 are Zumkeller numbers (A083207).at n=18A328327
• a(n) is the largest odd positive integer that is abundant and has the same prime signature as A279537(n) or 0 if no such integer exists.at n=43A343330
• Numbers > 1 that are not a prime power and whose prime indices and exponents are all themselves prime numbers.at n=34A352518
• Numbers k such that A360327(k) > 2*k.at n=10A360328
• Table of generalized de Bruijn's numbers (A006480) read by ascending antidiagonals.at n=32A361027
• a(n) = (3^3)*(1*2*4*5*7*8*10*11)*(3*n)!/(n!*(n+4)!^2).at n=4A361031