27157

Appears in sequences

• Strong pseudoprimes to base 54.at n=15A020280
• a(n) = 1 + n + n*[n/2] + n*[n/2]*[n/3] + n*[n/2]*[n/3]*[n/4] +... where [x]=floor(x).at n=12A075885
• Number of (n+1)X3 0..2 arrays with rows and columns of permanents of all 2X2 subblocks lexicographically nondecreasing, and all 2X2 permanents nonzero.at n=2A205229
• Number of (n+1) X 4 0..2 arrays with rows and columns of permanents of all 2 X 2 subblocks lexicographically nondecreasing, and all 2 X 2 permanents nonzero.at n=1A205230
• T(n,k)=Number of (n+1)X(k+1) 0..2 arrays with rows and columns of permanents of all 2X2 subblocks lexicographically nondecreasing, and all 2X2 permanents nonzero.at n=7A205235
• T(n,k)=Number of (n+1)X(k+1) 0..2 arrays with rows and columns of permanents of all 2X2 subblocks lexicographically nondecreasing, and all 2X2 permanents nonzero.at n=8A205235