24521

Appears in sequences

• Expansion of 1/((1-2x)(1-3x)(1-11x)).at n=4A016280
• Pseudoprimes to base 15.at n=30A020143
• Expansion of 1/((1-3x)(1-4x)(1-6x)(1-7x)).at n=4A028032
• a(i) is a square mod a(j), i <> j.at n=22A034903
• Nonnegative values x of solutions (x, y) to the Diophantine equation x^2+(x+16807)^2 = y^2.at n=7A118576
• Difference between squares of legs of primitive Pythagorean triangles, sorted (with multiplicity).at n=39A127923
• Difference between squares of legs of primitive Pythagorean triangles, sorted (with multiplicity).at n=40A127923
• A transform of the little Schroeder numbers.at n=13A185089
• a(n) gives the odd leg of one of the two Pythagorean triangles with hypotenuse A080109(n) = A002144(n)^2. This is the smaller of the two possible odd legs.at n=17A253802
• a(n) = greatest integer N such that (number of primes <= N) >= (number of numbers <= N that contain a zero in base n).at n=21A306526
• Number of prime parts in the partitions of n into 8 parts.at n=45A309437
• Nonsemiprimes in A306097 = A121707 \ A267999.at n=34A321488
• Numbers k for which A003973(k) is equal to 2*sigma(k).at n=16A337384
• a(n) = p(n)*p(n+1)*(p(n+1) - p(n)) - 1, where p(n) = prime(n).at n=17A383241
• a(n) = Sum_{k=0..n} 3^(n-k) * binomial(n+3,k+3) * binomial(2*k+6,k+6).at n=4A387276