19311

Appears in sequences

• Sum_{k=0..n^2} (k^2 - n^2)/n.at n=8A071902
• 1 + Sum_{k=2..n} 2^((prime(k)-1)/2).at n=9A080567
• Matrix cube of triangle A121412.at n=22A121420
• Column 1 of triangle A121420.at n=5A121422
• Rectangular table, read by antidiagonals, where row n is equal to column 1 of matrix power A121412^(n+1) for n>=0.at n=33A121426
• Number of subpartitions of partition P=[0,0,1,1,1,2,2,2,2,3,3,3,3,3,4,...] (A052146).at n=22A121431
• Triangle read by rows: T(n,k) is the number of nondecreasing Dyck paths of semilength n and having k double rises at an even level (n >= 1, k >= 0). A nondecreasing Dyck path is a Dyck path for which the sequence of the altitudes of the valleys is nondecreasing.at n=44A121531
• Number of distinct Tsuro tiles which are n-gonal in shape and have 2 points per side.at n=7A132102
• Square array, read by antidiagonals, where T(n,k) = T(n,k-1) + T(n-1,k+n+1) for n>0, k>0, such that T(n,0) = T(n-1,n+1) for n>0 with T(0,k)=1 for k>=0.at n=30A136737
• a(1) = 1; thereafter a(n) is always the smallest integer > a(n-1) not leading to a contradiction, such that the concatenation of any four consecutive digits in the sequence is a prime.at n=13A152609
• Number of nX5 0..1 arrays with every element equal to 0, 1, 4 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.at n=12A302677
• The number of five-term Egyptian fractions of rational numbers, x/y, 0 < x/y < 1, ordered as below. The sequence is the number of (p,q,r,s,t) such that x/y = 1/p + 1/q + 1/r + 1/s + 1/t where p, q, r, s, and t are integers with p < q < r < s < t.at n=7A349085
• The number of five-term Egyptian fractions of rational numbers, x/y, 0 < x/y < 1, ordered as below. The sequence is the number of (p,q,r,s,t) such that x/y = 1/p + 1/q + 1/r + 1/s + 1/t where p, q, r, s, and t are integers with p < q < r < s < t.at n=39A349085
• Numbers k such that Fibonacci(k) has a Fibonacci number of 1's in its binary representation.at n=57A382053