34230

Appears in sequences

• Expansion of e.g.f.: sech(arctan(x)+log(x+1))=1-4/2!*x^2+6/3!*x^3+77/4!*x^4-340/5!*x^5...at n=7A012971
• Numbers k such that the least term in the periodic part of the continued fraction for sqrt(k) is 74.at n=4A031752
• Triangle of coefficients of polynomials enumerating trees with n labeled nodes by inversions.at n=46A052121
• Triangle giving T(n,r) = number of equivalence classes of Boolean functions of n variables and range r=0..2^n under action of symmetric group.at n=43A052265
• a(n+1) = a(n) + (if a(n) is odd then (next odd square) else (next even square)), a(0) = 1.at n=30A116955
• Numerator of Bernoulli(n,5).at n=7A157930
• a(n) = 25*n^2 + 5.at n=36A158445
• Number of (n+1)X(n+1) -8..8 symmetric matrices with every 2X2 subblock having sum zero and three distinct values.at n=9A211467
• Numbers m such that the GCD of the x's that satisfy sigma(x) = m is 4.at n=37A241649
• Number of orbits of Aut(Z^7) as function of the infinity norm n of the representative lattice point of the orbit, when the cardinality of the orbit is equal to 26880.at n=36A266397
• Number of polygon edges formed when every pair of vertices of a regular n-gon are joined by an infinite line.at n=20A344899
• Number of polygon edges formed when every pair of vertices of a regular (2n-1)-gon are joined by an infinite line.at n=10A344907
• Triangular array read by rows. T(n,k) is the number of partial permutations on [n] with exactly k connected components, n>=0, 0<=k<=n.at n=32A350227