22770

Appears in sequences

• G.f.: 2*(1-x^3)/((1-x)^5*(1+x)^2).at n=43A005996
• a(n) = n*(n+1)*(2*n+1).at n=22A055112
• Largest area of a Pythagorean triangle with n as length of one of the three sides (in fact as a leg).at n=42A055522
• Integers k such that omega(k) = omega(k-1) + omega(k-2) + omega(k-3), where omega(n) is the number of distinct prime factors of n.at n=15A076252
• Even numbers k such that the central binomial coefficient A000984(k, k/2) is divisible by k^2.at n=11A080395
• Starting positions of strings of three 8's in the decimal expansion of Pi.at n=21A083637
• a(n) = T(n^3) - T(n^2), where T() are the triangular numbers (A000217).at n=6A085743
• Fifth column (m=4) of (1,6)-Pascal triangle A096956.at n=21A096958
• Fourth partial sums of fourth powers (A000583).at n=6A101091
• Numbers k such that (1_666.2_666.3_666 ... 8_666.9_666)*10^k + 1 is prime, i.e., 1 repeated 666 times, concatenated with 2 repeated 666 times, etc.at n=6A106488
• Numbers that have exactly six prime factors counted with multiplicity (A046306) whose digit reversal is different and also has 6 prime factors (with multiplicity).at n=36A109026
• Consider the sequence b(0)=127 and for n>0, b(n) is the least prime of the form k * b(n-1)^2 - 1 where k is a multiple of 6. This sequence gives the values of k.at n=11A110849
• Values of n associated with A123728.at n=6A123729
• Numbers k with the property that k^2 is a product of two distinct triangular numbers.at n=38A175497
• Number of (w,x,y,z) with all terms in {1,...,n} and 2|w-x|>n+|y-z|.at n=21A212689
• Smallest integer areas of integer-sided triangles such that the perimeter equals n times the smallest side.at n=45A237576
• a(n) = Sum_{0 < x,y,z <= n and gcd(x^2 + y^2 + z^2, n)=1} gcd(x^2 + y^2 + z^2 - 1, n).at n=22A239612
• a(n) = 56*2^n + 20*4^n + 35*3^n + 4*6^n + 10*5^n + 7^n + 84.at n=4A254466
• Sum over all Dyck paths of semilength n of products over all peaks p of x_p+y_p, where x_p and y_p are the coordinates of peak p.at n=5A258175
• Least positive integer k such that prime(k)-k, prime(k)+k, prime(k*n)-k*n, prime(k*n)+k*n, prime(k)+k*n and prime(k*n)+k are all prime.at n=32A259492