a(n) is the index of the smallest triangular number containing exactly n 3's.
A048358
a(n) is the index of the smallest triangular number containing exactly n 3's.
Terms
- a(0) =2a(1) =77a(2) =257a(3) =2570a(4) =816a(5) =25808a(6) =163299a(7) =812816a(8) =2463060a(9) =24629808a(10) =246306030a(11) =791999183a(12) =812812816a(13) =2581876578a(14) =81649658057a(15) =247924719918a(16) =812812812816
External references
- oeis: A048358