18520

Appears in sequences

• Numbers k such that 103*2^k+1 is prime.at n=14A032401
• Partitions with parts repeated at most twice and repetition only allowed if first part has an even index (first index = 1).at n=56A227135
• Number of (n+1) X (6+1) 0..3 arrays with nondecreasing x(i,j)-x(i,j-1) in the i direction and nondecreasing x(i,j)+x(i-1,j) in the j direction.at n=1A250875
• T(n,k)=Number of (n+1)X(k+1) 0..3 arrays with nondecreasing x(i,j)-x(i,j-1) in the i direction and nondecreasing x(i,j)+x(i-1,j) in the j direction.at n=22A250877
• Number of (2+1) X (n+1) 0..3 arrays with nondecreasing x(i,j)-x(i,j-1) in the i direction and nondecreasing x(i,j)+x(i-1,j) in the j direction.at n=5A250879
• a(n) = sum of the perimeters of the Ferrers boards of the partitions of n. Also, sum of the perimeters of the diagrams of the regions of the set of partitions of n.at n=20A278355
• Multiples of 1852.at n=10A303272
• a(1) = 102735, a(n) = prime(n-1)*a(n-1) but products that are not in A010784 are first reduced as in A320486 (see comments); continue until zero is reached.at n=15A321149
• Regular triangle read by rows: T(n,k) is the number of (n,k)-Duck words, for n>=1 and 0<=k<=n-1.at n=17A338403
• Row sums of a triangle based on A261327.at n=47A349118
• Numbers k >= 1 such that k^2 - r^2 is a repunit (A002275) for some 1 <= r < k.at n=22A389493