19799

Appears in sequences

• a(n) = (n^3 + 2*n)/3.at n=39A006527
• a(n) = (2*n+1)*(4*n^2+4*n+3)/3.at n=19A057813
• n*10^2-1, n*10^2-3, n*10^2-7 and n*10^2-9 are all prime.at n=26A064976
• a(n) = 900*n - 1.at n=21A158409
• a(n) = 22*n^2 - 1.at n=29A158540
• One third of product plus sum of three consecutive nonnegative integers; a(n)=(n+1)(n^2+2n+3)/3.at n=38A167875
• a(n) = n*(n+1)*(2*n+1)/6 - n*floor(n/2).at n=38A178946
• T(n,k)=Number of nXk arrays of nonnegative integers with rows and columns in lexicographically increasing order and some row sum or column sum equalling each of the values 1..n+k.at n=23A178990
• T(n,k)=Number of nXk arrays of nonnegative integers with rows and columns in lexicographically increasing order and some row sum or column sum equalling each of the values 1..n+k.at n=25A178990
• Sum of absolute values of real and imaginary parts of the coefficients in the expansion of 1 / (1 - x - I*x^2), where I^2=-1.at n=27A218137
• (p^2 - 3)/2 for odd primes p.at n=44A243887
• Fixed points of permutations A263265 and A263266.at n=16A263281
• Number of 7Xn integer arrays with each element equal to the number of horizontal and antidiagonal neighbors not equal to itself.at n=14A265997
• Number of 6Xn 0..1 arrays with every element equal to 0, 1, 3 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.at n=7A302639
• a(1) = 27846; thereafter a(n+1) = a(n) # n, where # is an operation that cycles through division, addition, subtraction and multiplication.at n=11A327962
• Number of partitions of n that do not have a fixed point that is also a fixed point of the conjugate partition.at n=38A374782