42120

Appears in sequences

• Least sum of 4 positive cubes in exactly n ways.at n=8A025420
• a(n) = (n-1)*(2*n-1)*(3*n-1)*(4*n-1).at n=7A033593
• a(n) = -Product_{k=0..n} (7*k-1); sept-factorial numbers.at n=4A049209
• Group the natural numbers so that the n-th group contains smallest set of consecutive numbers whose sum is a multiple of the sum for the previous group: (1), (2), (3, 4, 5), (6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18), (19, 20, ... Sequence gives sums of terms of the groups.at n=5A075631
• Sum of terms of n-th row of A077321.at n=19A077324
• Number of permutation polynomials over F_q of degree < q-2, as q runs through the prime powers >= 2.at n=6A078600
• Numbers k such that the product of Euler phi of the 2 consecutive integers {k,k+1} is a 4th power: if sqrt(sqrt(phi(k)*phi(k+1))) is an integer, then k is here.at n=13A082788
• Septuple factorial, 7-factorial, n!7, n!!!!!!!, a(n) = n*a(n-7) if n > 1, else 1.at n=27A114799
• a(n) = Sum_{i=1..n, j=1..n, gcd(i,j)=1} (n+1-i)*(n+1-j).at n=21A115004
• Triangle T(n,k) = number of forests of labeled rooted trees of height at most 1, with n labels, where each root contains k labels, n>=0, 0<=k<=n.at n=58A143398
• Exponential transform of binomial(n,3) = A000292(n-2).at n=10A145453
• Positive integers n such that n^2 = (x^4 - y^4)*(z^4 - t^4) where the pairs of integers (x,y) and (z,t) are not proportional.at n=31A147854
• Triangle sequence: T(n, k) = -Product_{j=0..k+1} ((n+1)*j - 1).at n=24A153187
• Triangle read by rows: T(n,k) = Product_{i=0..k-2} (i*n + n - 1).at n=18A153273
• a(n) = 4394*n - 1820.at n=9A156627
• Triangle of z Transform coefficients from General Pascal [1,10,1} A142459 polynomials multiplied by factor 3^Floor[(2*k - 1)/3].at n=19A167787
• Triangle related to T(x,2x).at n=59A171150
• Numbers k such that phi(k+1) = 4*phi(k).at n=5A172314
• Number of (n+4)X5 binary arrays with every 5X5 subblock commuting with each horizontal and vertical neighbor 5X5 subblock.at n=3A186601
• Number of (n+4)X8 binary arrays with every 5X5 subblock commuting with each horizontal and vertical neighbor 5X5 subblock.at n=0A186604