18218

Appears in sequences

• Convolution of Lucas numbers and primes.at n=14A023625
• Numbers k such that the continued fraction for sqrt(k) has odd period and if the last term of the periodic part is deleted the two central terms are both 11.at n=18A031599
• Maximal number of regions into which 4-space can be divided by n hyperspheres.at n=23A059173
• Number of permutations of 1..n containing the relative rank sequence { 236514 } at any spacing.at n=3A159151
• Number of nondecreasing arrangements of n+3 numbers in 0..3 with each number being the sum mod 4 of three others.at n=42A183898
• Numbers n such that n!8-1 is prime.at n=56A204662
• Number of n X n 0..3 arrays x(i,j) with each element horizontally or vertically next to at least one element with value (x(i,j)+1) mod 4, and upper left element zero.at n=3A230244
• Number of nX4 0..3 arrays x(i,j) with each element horizontally or vertically next to at least one element with value (x(i,j)+1) mod 4, and upper left element zero.at n=3A230247
• T(n,k)=Number of nXk 0..3 arrays x(i,j) with each element horizontally or vertically next to at least one element with value (x(i,j)+1) mod 4, and upper left element zero.at n=24A230250
• a(n) = Sum_{k=1..n-1} sigma_5(k)*sigma_5(n-k).at n=4A279889
• b(0) = 1, b(2*n-1) = 1/(1+1^2/(1+1^2/(1+2^2/(1+2^2/(...+(n-1)^2/(1+n^2)))))) and b(2*n) = 1/(1+1^2/(1+1^2/(1+2^2/(1+2^2/(...+n^2/(1+n^2)))))). a(n) is the numerator of b(n).at n=9A292816
• Numbers k such that (35*10^k - 737)/9 is prime.at n=17A295397
• Number of distinct hook length sets of partitions of n.at n=45A301512
• Expansion of Product_{k>=1} 1/((1 - x^k)*(1 - x^(5*k))).at n=33A318028
• Product_{n>=1} (1 + x^n)^a(n) = 1 + x + Sum_{n>=2} prime(n-1) * x^n.at n=53A353161