786426

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=34A061776
• a(1) = 1; thereafter a(n) = 6*(2^(n-1) - 1).at n=17A068293
• The smallest superharmonic number with index n.at n=15A152573
• Positions of zeros in A165477.at n=12A165478
• 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=25A179697
• Even integers k such that phi(sum of even divisors of k) = sum of odd divisors of k.at n=22A281707