141814domain: NAppears in sequencesSmallest multiple of the n-th prime beginning and ending in n with a(1)=a(3)=0.at n=13A078212Total number of consecutive triples matching the pattern 132 in all faro permutations of length n.at n=17A340568a(n) = Sum_{k=1..n-1} sigma(k) * sigma_2(n-k).at n=30A374974