24412

Appears in sequences

• Number of maximal collections of pairwise disjoint subsets {X,Y,Z} of {1, 2, ..., n} with X + Y = Z (as in A002849), with the property that n is in one of the subsets.at n=21A002848
• a(1)=1, a(n) = 5*a(n-1) + n.at n=6A014827
• Let M(n) be the n X n matrix m(i,j)=min(i,j) for 1<=i,j<=n; then a(n) is the trace of M(n)^(-7).at n=8A114359
• Numbers k such that (11*10^k - 131)/3 is prime.at n=20A282635
• a(n) is the largest integer k such that sigma(k)/(d(k)*sopf(k)) = n where d=A000005, sigma=A000203 and sopf=A008472.at n=9A328175