20304

Appears in sequences

• a(n) = (5*n+1)*(5*n+4).at n=28A001545
• Number of self-avoiding walks on hexagonal lattice.at n=5A007201
• Cycle class sequence c(n) (the number of true cycles of length n in which a certain node is included) for zeolite DAC = Dachiardite Na5[Al5Si19O48].12H2O starting with a T1 atom.at n=13A019102
• Positive numbers k such that (k+1)*(k+2)*(k+3)*(k+4)/(k+(k+1)+(k+2)+(k+3)+(k+4)) is an integer.at n=26A032795
• Sum_{i=0..2n} (C(2n,i) mod 2)*Fibonacci(i+2) = Sum_{i=0..n} (C(n,i) mod 2)*Fibonacci(2i+2).at n=10A048757
• a(n) = 18*(n - 2)*(2*n - 5).at n=24A060787
• Numbers n divisible by exactly two nontrivial permutations (rearrangements) of the digits of n.at n=18A090057
• Numbers k such that T(k) + T(k+1) + ... + T(k+10) is a square, where T(m) = A000217(m) is the m-th triangular number.at n=5A116476
• The sum of all the entries in an n X n Cayley table for multiplication in Z_n.at n=35A160255
• Numbers of the form p^4*q^3*r where p, q, and r are distinct primes.at n=26A179698
• Table of the elementary symmetric functions a_k(1,2,3,4,6,...,n+1) (5 missing).at n=34A196844
• (n-1)-st elementary symmetric function of the first n terms of (2,3,1,2,3,1,2,3,1,...)=A010882.at n=12A203160
• Number of 2 X 2 nonsingular matrices having all terms in {1,...,n}.at n=11A211056
• The Wiener index of the cyclic phenylene with n hexagons (n>=3).at n=9A224456
• The greedy sequence of real numbers at least 1 that do not contain any 3-term geometric progressions with integer ratio.at n=23A235054
• Number of right triangles on a centered hexagonal grid of size n.at n=6A241225
• For increasing z > 0, integers, y - x, where x^3 + y^3 = z^3 + 1, with y > x > 1.at n=20A259753
• Irregular triangle read by rows: row n consists of the coefficients of the expansion of the polynomial (2*x + 2)^n + (x^2 - 1)*(x + 2)^n.at n=70A300184
• a(1) = 50 and for any n > 0, a(n+1)^2 is the smallest square that begins with a(n).at n=28A309123
• Number of balanced p-trees with n leaves.at n=26A316624