405450

Appears in sequences

• a(n) = n^2*(n^2 + 1)/2.at n=30A037270
• Numbers k that can be expressed as k = w + x = y*z with w*x = y^2 + z^2 where w, x, y, and z are all positive integers.at n=30A057373
• Sum of next n numbers/n if n divides the sum else n times the sum of next n numbers.at n=29A094260
• Triangular numbers composed of digits {0,4,5}.at n=5A119071
• Sophie Germain triangular numbers tr: 2*tr+1 is also a triangular number.at n=8A124174
• a(n) = A185128(n) - A185129(n).at n=19A185253
• Define the array k(n,x) = number of m such that tau(gcd(n,m)) is x where m runs from 1 to n. Also define h(n,x) = Sum_{d|n : tau(d) = x} d. The sequence contains numbers n such that k(n,x)*x = h(n,x) has at least one solution x.at n=24A197099
• Sequences A124174 and A006454 interlaced.at n=16A217278
• Number of n-digit numbers that yield an n-digit number after Reverse and Add.at n=5A232729
• Triangular numbers n such that each decimal digit of n is equal to the difference of at least two other digits of n.at n=26A255917
• Triangular numbers that are sum of squares of two distinct triangular numbers.at n=37A346386
• Triangular numbers that are palindromes in base 7.at n=14A350992