422740domain: NAppears in sequencesa(n) = smallest triangular number having no digit in common with the previous term, with a(1) = 1.at n=35A068818a(n) = (9n^4 - 18n^3 + 18n^2 - 9n + 2)/2.at n=17A079903The first of three consecutive hexagonal numbers the sum of which is equal to the sum of three consecutive primes.at n=17A298272