49146

Appears in sequences

• Start with a single triangle; at n-th generation add a triangle at each vertex, allowing triangles to overlap; sequence gives number of triangles in n-th generation.at n=26A061776
• a(1) = 1; thereafter a(n) = 6*(2^(n-1) - 1).at n=13A068293
• a(n) = min{ m : sum_{n <= i <= m} 1/p_i > 1}, where p_i is the i-th prime = A000040(i).at n=30A092325
• Smallest number m such that sigma(m) is an n-almost prime.at n=15A152092
• The smallest superharmonic number with index n.at n=11A152573
• Number of ways that a 1 X n rectangular tile T, marked into n unit squares, can be surrounded by one layer of copies of itself laid in the plane grid generated by the units of T. Ways that differ by rotation or reflection are not counted as different. The surrounded tile is the exact surrounded region.at n=22A159294
• Base-10 representation of numbers k which, in base 2, satisfy abs(k + reverse(k) - reverse(k + reverse(k))) = abs(k - reverse(k)) + reverse(abs(k - reverse(k))) = k.at n=11A179697
• Triangle read by rows: denominator of h(n-k)*h(k)/h(n) where h(x) = zeta(2*x)*(4^x-2), 0<=k<=n.at n=30A246052
• Triangle read by rows: denominator of h(n-k)*h(k)/h(n) where h(x) = zeta(2*x)*(4^x-2), 0<=k<=n.at n=33A246052
• Even numbers such that the sum of the even divisors and the sum of the odd divisors are a square or a cube.at n=38A263695
• Even integers k such that phi(sum of even divisors of k) = sum of odd divisors of k.at n=15A281707
• Consecutive states of the linear congruential pseudo-random number generator 228*s mod (2^16+1) when started at s=1.at n=37A385079