21604

Appears in sequences

• Let A(n) = #{(i,j): i^2 + j^2 <= n}, V(n) = Pi*n, P(n) = A(n) - V(n); sequence gives values of n where |P(n)| sets a new record.at n=42A000099
• Coordination sequence for alpha-Mn, Position Mn2.at n=38A009951
• Number of dissectable polyhedra with n tetrahedral cells and symmetry of type H.at n=32A047754
• a(n) = A047752(12n+5).at n=8A047755
• Duplicate of A047755.at n=8A047757
• Number of dissectable polyhedra with n tetrahedral cells with symmetry of type N or chiral pairs with symmetry of type O.at n=49A047766
• a(n) = A047766(6n+2).at n=8A047768
• Number of chiral pairs of dissectable polyhedra with n tetrahedral cells and symmetry of type M.at n=15A047769
• a(n) = A047769(2n).at n=7A047770
• Number of chiral pairs of dissectable polyhedra with n tetrahedral cells and symmetry of type C.at n=24A047774
• Numbers k such that 9*10^k + 7 is prime.at n=24A096774
• Alkane systems (see Cyvin reference for precise definition).at n=15A121180
• Index of Mersenne number A000225 that is also Mersenne prime A000668, minus n-th prime: a(n) = A000043(n) - A000040(n).at n=24A153801
• Number of line segments connecting exactly 3 points in an n X n grid of points.at n=22A177719
• a(n) = number of regions in the configuration A290447(n).at n=28A290865
• a(n) is the number of overpartitions of n where overlined parts are not divisible by 3 and non-overlined parts are congruent to 1 modulo 3.at n=44A335754