5000050000
domain: N
Appears in sequences
- Smallest triangular number containing exactly n 0's.at n=7A036517
- a(n) = 10^n*(10^n+1)/2.at n=5A037156
- Triangular numbers that contain exactly 2 different digits.at n=37A062691
- 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=24A068812
- Triangular numbers containing 2n digits obtained by duplicating the first n digits; i.e., triangular numbers in A020338.at n=17A068899
- Triangular numbers with arithmetic mean of digits = 1 (sum of digits = number of digits).at n=16A069790
- a(n) = (n^10 + n^5)/2.at n=10A071236
- Triangular numbers composed of digits {0,1,5}.at n=25A119039
- Triangular numbers composed of digits {0,2,5}.at n=8A119051
- Triangular numbers composed of digits {0,3,5}.at n=7A119061
- Triangular numbers composed of digits {0,4,5}.at n=14A119071
- Triangular numbers composed of digits {0,5,6}.at n=14A119079
- Triangular numbers composed of digits {0,5,7}.at n=6A119081
- Triangular numbers composed of digits {0,5,8}.at n=4A119083
- Triangular numbers composed of digits {0,5,9}.at n=10A119085
- Number of classes of endofunctions of [n] under reversal.at n=10A275549
- Triangular numbers whose nonzero digits are all the same.at n=17A352057
- Kaprekar numbers that are the concatenation of two equal numbers.at n=21A381917
- Kaprekar numbers (A006886) that are divisible by the sum of their digits.at n=41A382165