254541

Appears in sequences

• Triangular numbers with property that digits alternate in parity individually as well as in concatenation with previous terms.at n=29A068889
• Lowest base with simple divisibility test for n primes; smallest B such that omega(B) + omega(B-1) = n.at n=9A069354
• Triangular numbers composed of only digits with line segments or both line segments and curves {1, 2, 4, 5, 7}.at n=34A247021
• Number of length 5 1..(n+1) arrays with every leading partial sum divisible by 2, 3, 5 or 7.at n=14A258636
• Hexagonal numbers (A000384) in which parity of digits alternates.at n=27A297645
• Triangular numbers T(i) that can be expressed as the sum of 2 positive triangular numbers, T(j)+T(k), and for which i+j+k is a triangular number, where T is A000217.at n=12A343426