1, 3, 6, 10, 15, 21, 28, 36
Chat with our AI personalities
The answer would be 15 and 21. The triangular numbers are 1,3,6,10,15,21,28,36,45,55,66,78. 15 plus 21 is 36 which is on the list. 21 minus 15 is 6 and that is on the list as well.
No - but it is a square number. 1,3,6,10,15,21 & 28 are all triangular numbers. 1,4,9,16,25 & 36 are all square numbers.
no- 29 is not triangular. The triangular numbers closest to 29 are 28 and 36.
1, 3, 6, 10, 15, 21, 28, 36, 45, 55, 66, 78, 91, 104, ...
101