107880

Appears in sequences

• [ n(n-1)(n-2)(n-3)/7 ].at n=31A011917
• sech(sinh(x)+tan(x))=1-4/2!*x^2+56/4!*x^4-1798/6!*x^6+107880/8!*x^8...at n=4A013055
• Positive numbers k such that k and 8*k are anagrams in base 9 (written in base 9).at n=13A023085
• Number of ways to place 3 nonattacking queens on an n X n board.at n=11A047659
• Tritriangular numbers: a(n) = binomial(binomial(n,2),2) = n*(n+1)*(n-1)*(n-2)/8.at n=31A050534
• Consider 2n tennis players; a(n) is the number of matches needed to let every possible pair play each other.at n=14A062346
• Areas of Pythagorean triangles (A069482, A069484, A069486).at n=9A069487
• Expansion of 120*x^2 / (-x^3+899*x^2-899*x+1).at n=2A157879
• Triangular numbers which are sums of 4 consecutive primes.at n=13A173420
• Triangular numbers k whose divisors can be partitioned into three disjoint sets whose sums are all sigma(k)/3.at n=34A206025
• Numbers n such that n = concatenate(a, b) and sigma(a) + sigma(b) = phi(n).at n=10A249065
• 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=15A255917
• Imaginary part of (n + i)^4.at n=30A272871
• Integers m such that A342805(m) = m+3.at n=40A342806
• 32*a(n) is the denominator of the squared circumradius of a cyclic quadrilateral with sides n, n+1, n+2, n+3.at n=28A351697
• a(n) is the first number that is the sum of two palindromic primes in exactly n ways.at n=12A379138