31487

Appears in sequences

• a(n) = dot_product(1,2,...,n)*(3,4,...,n,1,2).at n=43A026037
• Numbers whose set of base-13 digits is {1,4}.at n=36A032825
• Numbers k such that sopf(k) = sopfr(k+1), where sopf(k) = A008472(k) and sopfr(k) = A001414(k).at n=32A064678
• a(n) = 8 + floor((2 + Sum_{j=1..n-1} a(j))/4).at n=37A120166
• Numbers k such that k!! - 2^k is prime.at n=24A124249
• Number of nX4 0..2 arrays with no more than floor(nX4/2) elements unequal to at least one horizontal, vertical or antidiagonal neighbor, with new values introduced in row major 0..2 order.at n=5A222645
• Number of nX6 0..2 arrays with no more than floor(nX6/2) elements unequal to at least one horizontal, vertical or antidiagonal neighbor, with new values introduced in row major 0..2 order.at n=3A222647
• T(n,k)=Number of nXk 0..2 arrays with no more than floor(nXk/2) elements unequal to at least one horizontal, vertical or antidiagonal neighbor, with new values introduced in row major 0..2 order.at n=39A222649
• T(n,k)=Number of nXk 0..2 arrays with no more than floor(nXk/2) elements unequal to at least one horizontal, vertical or antidiagonal neighbor, with new values introduced in row major 0..2 order.at n=41A222649
• a(n) = 23*n^2.at n=37A244632
• Odd numbers k such that A173557(k) = A173557(sigma(k)), where A173557(n) is multiplicative with a(p^e) = p-1 and sigma is the sum of divisors function.at n=31A387159