101640

Appears in sequences

• Number of ways to cover (without overlapping) a ring lattice (necklace) of n sites with molecules that are 5 sites wide.at n=40A058368
• Numbers that can be expressed as the difference of the squares of primes in exactly ten distinct ways.at n=5A092006
• Numbers with exactly 5 distinct prime divisors {2,3,5,7,11}.at n=30A147572
• Number of 1..3 integer arrays v[1..n] of length n with all autocorrelation values sum(i){v[i]*v[i-k]} distinct for k in 0..n-1.at n=10A171277
• Number of 1..n integer arrays v[1..11] of length 11 with all autocorrelation values sum(i){v[i]*v[i-k]} distinct for k in 0..10.at n=2A171348
• Partial sums of A072857.at n=21A173052
• Fast "exotic addition" a o b = [ a[1]+b[1], a[1]*b[2]+a[2]*b[1] ].at n=41A175841
• Numbers which are the area of exactly three Pythagorean triangles.at n=14A177021
• Numbers with prime factorization p*q*r*s^2*t^3 (where p, q, r, s, t are distinct primes).at n=32A190111
• Number of solutions to x^2 + y^2 + z^2 + t^2 == n (mod 2*n) for x,y,z,t in [0, 2*n).at n=20A229294
• Expansion of ( f(-q)^12 + 22 * q * f(-q)^6 * f(-q^5)^6 + 125 * q^2 * f(-q^5)^12 ) / (f(-q) * f(-q^5))^2 in powers of q where f() is a Ramanujan theta function.at n=20A235870
• Number of non-congruent solutions of x^2 + y^2 + z^2 + t^2 == 0 mod n.at n=41A240547
• a(n) = Sum_{j=0..n/2} binomial(n-j-1,n-2*j)*binomial(2*n+1,j).at n=10A278618
• Number of 2 X 2 matrices with entries in {0,1,...,n} and even trace with no entries repeated.at n=22A280056
• Number of n-element subsets of [n+8] having an even sum.at n=13A282084
• Number of maximal independent vertex sets (and minimal vertex covers) in the n-wheel graph.at n=38A290612
• Number of non-congruent solutions of x^2+y^2 == z^2+w^2 (mod n).at n=41A316148
• Triangle T(n,m) = C(2*n,m)*C(2*n-1,n), 0 <= m <= 2*n, n >= 0.at n=39A320327
• Triangle T(n,m) = C(2*n,m)*C(2*n-1,n), 0 <= m <= 2*n, n >= 0.at n=45A320327
• Number of ordered set partitions of [n] where the maximal block size equals seven.at n=4A320763