50403

Appears in sequences

• Odd triangular numbers with prime indices.at n=31A034954
• Base 5 digits are, in order, the first n terms of the periodic sequence with initial period 3,1,0.at n=6A037661
• a(1) = 1; a(n) is the smallest triangular number > a(n-1) which differs from it at every digit.at n=32A068855
• Triangular numbers obtained as a concatenation of successive terms of A081847.at n=5A082235
• Numbers k such that (k+j) mod (2+j) = 1 for j from 0 to 8 and (k+9) mod 11 <> 1.at n=18A096026
• Smallest triangular number greater than n! with the same leading digits as n!.at n=6A096564
• Triangular numbers for which the sum of the digits is a pentagonal number.at n=28A117305
• Numerators of domain values whose images via the flowsnake Q-function follow a spiral trajectory (see comments).at n=12A262147
• Triangular numbers that in base 2 have the same number of 0's and 1's.at n=36A345348
• Hexagonal numbers that are sphenic numbers.at n=33A380007