1719585

Appears in sequences

• Numbers n such that n and its 10's complement are both triangular numbers; that is, n and 10^k - n (where k is the number of digits in n) are triangular numbers.at n=14A068812
• Partial sums of dodecahedral numbers (A006566).at n=35A116689
• Triangular numbers n such that sigma(n) is a square number.at n=39A256151