24420

Appears in sequences

• Short leg of primitive Pythagorean triangles having legs that add up to a square, sorted on hypotenuse.at n=27A089547
• a(0)=1; a(n) = sigma_1(n) + sigma_3(n).at n=29A092345
• Expansion of g.f.: (1-4*x)/((1-5*x)*(1-x)^2).at n=7A094195
• Array, A(n, k) = ((n+2)^(k+1) + (k+1)*n*(n+1) - 1)/(n+1)^2, read by antidiagonals.at n=62A094250
• (1/8)*number of lattice points with odd indices in a cubic lattice inside a sphere around the origin with radius 2*n.at n=35A120884
• a(n) = f(f(f(f(f(n))))), where f(n) is prime(n)-1.at n=8A141139
• a(n) = prime(prime(prime(prime(n) - 1) - 1) - 1) - 1, where prime(n) is the n-th prime.at n=21A141217
• A145312(n)/1440.at n=9A145346
• 12 times pentagonal numbers: a(n) = 6*n*(3*n-1).at n=37A153792
• Numbers that have 10 terms in their Zeckendorf representation.at n=15A179250
• Number of nX5 0..1 arrays avoiding 0 0 0 and 0 1 0 horizontally and 0 0 1 and 1 1 1 vertically.at n=7A207690
• Number of n X 4 0..1 arrays avoiding 0 0 0 and 1 1 1 horizontally and 0 0 1 and 1 0 1 vertically.at n=33A208375
• Primitive triangle numbers as defined in A218243.at n=37A218392
• Numbers k having at least two complementary pairs of divisors (q, p) and (p', q') such that k = p*q = p'*q' where the decimal digits of p' are the 9's complement of the decimal digits of p and the decimal digits of q' are the 9's complement of the decimal digits of q.at n=15A226587
• Number of (n+1) X (2+1) 0..4 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 4 (constant-stress 1 X 1 tilings).at n=5A234558
• Number of (n+1) X (6+1) 0..4 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 4 (constant-stress 1 X 1 tilings).at n=1A234562
• T(n,k) is the number of (n+1) X (k+1) 0..4 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 4 (constant-stress 1 X 1 tilings).at n=22A234564
• T(n,k) is the number of (n+1) X (k+1) 0..4 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 4 (constant-stress 1 X 1 tilings).at n=26A234564
• a(n) = n*(n^2 - 3*n + 4).at n=30A242659
• a(n) = n*(2^(n-1) - n - 1).at n=9A342482