200028

Appears in sequences

• a(n) = smallest triangular number having no digit in common with the previous term, with a(1) = 1.at n=33A068818
• Triangular numbers for which the sum of the digits is a pentagonal number.at n=36A117305
• Triangular numbers with only even digits.at n=17A117978
• Triangular numbers composed of digits {0,2,8}.at n=4A119055
• Triangle read by rows: T(n,m) (n >= m >= 1) = number of edges in the graph formed by drawing the line segments connecting any two of the (n+1) X (m+1) lattice points in an n X m grid of squares.at n=27A333278