18992

Appears in sequences

• Numbers k such that k^2 - 1 is a palindrome.at n=18A070253
• Number of weakly regular simple graphs on n nodes.at n=11A076434
• a(n) = 5^n + 4^n - 3^n.at n=6A083320
• Number of permutations p of {1,...,n} satisfying p(1)=1 and, if n>1, |p(i)-p((i mod n)+1)| is in {2,3} for i from 1 to n.at n=44A174469
• Expansion of g.f. 1/ (1-x^1*(1-x^(m+1))/ (1-x^2*(1-x^(m+2))/ (1- ... ))) for m=10.at n=20A185649
• Number of -3..3 arrays x(i) of n+1 elements i=1..n+1 with set{t,u,v in 0,1}((x[i+t]+x[j+u]+x[k+v])*(-1)^(t+u+v)) having four distinct values for every i,j,k<=n.at n=12A211720
• Smooth necklaces with 5 colors.at n=11A215331
• Number of (n+1) X (1+1) 0..3 arrays with the minimum plus the maximum unequal to the lower median plus the upper median in every 2 X 2 subblock.at n=2A235926
• Number of (n+1)X(3+1) 0..3 arrays with the minimum plus the maximum unequal to the lower median plus the upper median in every 2X2 subblock.at n=0A235928
• T(n,k)=Number of (n+1)X(k+1) 0..3 arrays with the minimum plus the maximum unequal to the lower median plus the upper median in every 2X2 subblock.at n=3A235932
• T(n,k)=Number of (n+1)X(k+1) 0..3 arrays with the minimum plus the maximum unequal to the lower median plus the upper median in every 2X2 subblock.at n=5A235932
• Number of partitions of n with difference -8 between the number of odd parts and the number of even parts, both counted without multiplicity.at n=49A242684
• Numbers equal to the arithmetic derivative of their Euler totient function.at n=38A248815
• Number of n X 7 0..1 arrays with every element equal to 0, 1, 3 or 4 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.at n=5A302308
• Number of 6Xn 0..1 arrays with every element equal to 0, 1, 3 or 4 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.at n=6A302314
• Sum of the squarefree parts of the partitions of n into 7 parts.at n=32A309482
• Number of integer partitions of n that can be partitioned into two or more blocks with equal sums.at n=39A321452
• Numbers k such that the k-th composition in standard order is an alternating permutation of {1..k} for some k.at n=35A349051
• Expansion of e.g.f. (1/x) * Series_Reversion( x * (exp(-2*x) - x) ).at n=4A379661