26568

Appears in sequences

• Numbers whose base-5 representation contains exactly three 2's and three 3's.at n=30A045277
• Values of n^2 - 1 resulting from A050795.at n=15A050799
• Numbers k such that the squarefree part of k equals A062799(k).at n=35A069551
• Expansion of 1/((1-x)*(1+x+x^2+2*x^3)).at n=38A077909
• a(n) = 6*a(n-1) - 6*a(n-2), with a(0)=1, a(1)=3.at n=7A083881
• a(n) = (prime(n)-1)*(prime(n)+1).at n=37A084920
• a(0)=1, a(1)=3, a(n) = floor((Pi + 1/Pi)*a(n-1) - a(n-2)).at n=9A085839
• a(1) = floor(Pi) = 3; a(n+1) = floor(a(n)*Pi).at n=8A115239
• a(0) = 1, a(n) = floor(a(n - 1)*Pi).at n=9A134915
• Eight times hexagonal numbers: a(n) = 8*n*(2*n-1).at n=41A152750
• a(n) = sinh(2*arcsinh(n))^2 = 4*n^2*(n^2 + 1).at n=9A173116
• Numbers of the form p^4*q^3*r where p, q, and r are distinct primes.at n=33A179698
• Product of n and the sum of remainders of n mod k, for k = 1, 2, 3, ..., n.at n=53A256532
• p-INVERT of the odd positive integers, where p(S) = 1 + S - 2 S^2.at n=10A292491
• Number of regions formed when every pair of vertices of a regular n-gon are joined by an infinite line.at n=23A345025
• Numbers k such that k and k+1 both have more nonunitary than unitary prime divisors (A348121).at n=27A348122
• Numbers sandwiched between two semiprimes, one of which is a square.at n=28A358686
• a(n) is the number of solutions to gcd(a^2 + b^2, p) = 1 where p is the n-th prime and 0 <= a,b <= p-1.at n=37A360323
• Square array T(n,k), n >= 0, k >= 0, read by antidiagonals downwards, where T(n,k) = Sum_{j=0..floor(n/2)} k^(n-j) * binomial(n,2*j).at n=62A361432
• Triangle read by rows: T(n,k) is the number of crystallized linear chord diagrams on n chords with k short chords.at n=30A375504