265356

Appears in sequences

• a(n) = 3^n*(3^n-1)/2.at n=6A026121
• Number of reversible strings with n beads of 3 colors. If more than 1 bead, not palindromic.at n=11A032086
• Number of primitive (aperiodic) palindromic structures using a maximum of three different symbols.at n=26A056477
• Smallest triangular number having n^2 as divisor.at n=26A080983
• a(n) = n^2 * (n^2 - 1)/2.at n=26A083374
• a(n) = A000217(n^3) - n^3.at n=9A085744
• Triangular numbers which are 10-almost primes.at n=5A101744
• Triangular numbers for which the sum of the digits equals the sum of the digits of the next triangular number.at n=35A117511
• Expansion of x^2/((3*x-1)*(3*x^2-1)).at n=13A167993
• Let T(n) = n(n+1)/2 be the n-th triangular number (A000217); a(n) = T(8T(n)).at n=13A185096
• Square array A(n,k), n>=0, k>=0, read by antidiagonals: A(n,k) is the number of n-element subsets that can be chosen from {1,2,...,2*n^k} having element sum n^(k+1).at n=48A185282
• Number of 2 X 2 matrices with all terms in {0,1,...,n} and odd trace.at n=26A210379
• Least triangular number that is the product of n triangular numbers greater than 1.at n=5A212616
• Least triangular number that is the product of n triangular numbers greater than 1.at n=6A212616
• Triangular numbers that are the product of three distinct triangular numbers greater than 1.at n=28A225440
• Triangular numbers divisible by the square of the sum of their digits.at n=13A243008
• Triangular numbers that are the product of a triangular number and a square number (both greater than 1).at n=13A253650
• Triangular numbers that are the product of a triangular number and an oblong number.at n=34A253652
• Refactorable triangular numbers.at n=32A272524
• Expansion of (a(q) / b(q))^3 in powers of q where a(), b() are cubic AGM theta functions.at n=6A290405