461280

Appears in sequences

• Smallest triangular number which is a multiple (>1) of the n-th triangular number.at n=30A068084
• Triangular numbers which are 9-almost primes.at n=13A076583
• Smallest triangular number having n^2 as divisor.at n=30A080983
• a(n) = n^2 * (n^2 - 1)/2.at n=30A083374
• Number of n X n matrices over GF(5) with rank n-1.at n=2A086778
• a(n) = ((n-th prime)^4-(n-th prime)^2)/2.at n=10A138418
• Let T(n) = n(n+1)/2 be the n-th triangular number (A000217); a(n) = T(8T(n)).at n=15A185096
• Number of nX3 0..2 arrays with no element equal the average of immediate neighbors vertically above, diagonally above and left, and horizontally left of it.at n=4A208791
• Number of nX5 0..2 arrays with no element equal the average of immediate neighbors vertically above, diagonally above and left, and horizontally left of it.at n=2A208793
• T(n,k)=Number of nXk 0..2 arrays with no element equal the average of immediate neighbors vertically above, diagonally above and left, and horizontally left of it.at n=23A208796
• T(n,k)=Number of nXk 0..2 arrays with no element equal the average of immediate neighbors vertically above, diagonally above and left, and horizontally left of it.at n=25A208796
• Number of 2 X 2 matrices with all terms in {0,1,...,n} and odd trace.at n=30A210379
• Numbers whose sum of proper square divisors is a palindrome in base 10 having at least two digits.at n=31A232892
• Numbers whose sum of square divisors is a palindrome in base 10 having at least two digits.at n=18A232893
• Triangular numbers that are the product of a triangular number and a square number (both greater than 1).at n=15A253650
• Triangular numbers that are the product of a triangular number and an oblong number.at n=41A253652