223884

Appears in sequences

• a(n) = (n+1)*a(n-1) + a(n-2), with a(0)=0, a(1)=1.at n=8A058307
• Triangle with a(n,n)=1, a(n,k)=(n-1)*a(n-1,k)+a(n-2,k) for n>k.at n=58A062323
• Triangle read by rows. Let S(k) be the sequence defined by F(0)=0, F(1)=1, F(n-1) + (n+k)*F(n) = F(n+1). E.g. S(0) = 0, 1, 1, 3, 10, 43, 225, 1393, 9976, 81201, ... Then S(0), S(1), S(2), ... are written vertically, next to each other, with the initial term of each on the next row down.at n=47A102472
• Triangle read by rows. Let S(k) be the sequence defined by F(0)=0, F(1)=1, F(n-1) + (n+k)*F(n) = F(n+1). E.g. S(0) = 0,1,1,3,10,43,225,1393,9976,81201, ... Then S(0), S(1), S(2), ... are written next to each other, vertically, with the initial term of each on the next row down. The order of the terms in the rows are then reversed.at n=52A102473
• Incorrect duplicate of A058307.at n=8A121954
• Triangle read by rows: T(n,k) = (n-1)*T(n-1,k) + T(n-2,k), with T(n,n-1)=1, T(n,n-2)=n-2, for n >= 1, 0 <= k <= n-1.at n=45A228340
• T(n,k) = 2*(K(n,2)*I(k,2) - (-1)^(n+k)*I(n,2)*K(k,2)), where I(n,x) and K(n,x) are Bessel functions; triangle read by rows for 0 <= k <= n.at n=57A246654
• G.f.: x * Product_{j>=1, k>=1} 1/(1 - a(j)*x^(j*k)).at n=13A308153
• Number of maximal subsets of {1..n} such that it is possible to choose a different prime factor of each element.at n=40A370585
• Number of maximal subsets of {1..n} such that it is possible to choose a different prime factor of each element.at n=41A370585
• Number of maximal subsets of {1..n} containing n such that it is possible to choose a different prime factor of each element (choosable).at n=41A370590