18527

Appears in sequences

• a(n) = Sum_{k=0..n-2} T(n,k) * T(n,k+2), with T given by A026659.at n=6A026978
• a(n) = smallest multiple of prime(n) such that a(n) +1 is a multiple of prime(n+1).at n=42A077338
• Numbers k such that sigma(phi(k))-phi(sigma(k)) is nonzero and is divisible by (k+1), that is A065395(k)/(k+1) = (phi(sigma(k))-sigma(phi(k)))/(k+1) is a nonzero integer.at n=13A092586
• Number of permutations of length n which avoid the patterns 312, 1324, 3421; or avoid the patterns 312, 1324, 2341, etc.at n=26A116722
• A156977/3.at n=27A164565
• Partial sums of A050508.at n=32A178129
• Numbers of the form p*q, p and q prime with q=2p-3.at n=15A226755
• Number of (n+1)X(1+1) 0..2 arrays with the maximum plus the lower median minus the minimum of every 2X2 subblock equal.at n=4A236812
• Number of (n+1)X(5+1) 0..2 arrays with the maximum plus the lower median minus the minimum of every 2X2 subblock equal.at n=0A236816
• T(n,k)=Number of (n+1)X(k+1) 0..2 arrays with the maximum plus the lower median minus the minimum of every 2X2 subblock equal.at n=10A236819
• T(n,k)=Number of (n+1)X(k+1) 0..2 arrays with the maximum plus the lower median minus the minimum of every 2X2 subblock equal.at n=14A236819
• a(n) = A273059(4n+3).at n=23A275919
• Least k such that A000790(k) = A108574(n).at n=32A326610