21306

Appears in sequences

• Denominators of convergents to the diesis log_2(5/4).at n=9A046104
• A list of equal temperaments (equal divisions of the octave) whose nearest scale steps are closer and closer approximations to the pair of ratios 5/4 and 8/5 which generate two complementary tones of musical harmony, the Major 3rd (5/4) and the Minor 6th (8/5).at n=19A061918
• Duplicate of A046104.at n=9A116984
• Number of ways to place zero or more nonadjacent 1,1 2,0 2,1 2,2 3,1 4,1 4,2 polyhexes in any orientation on a planar nXnXn triangular grid.at n=7A155317
• Number of binary strings of length n with equal numbers of 00011 and 11000 substrings.at n=15A164233
• Number of ways to write n as an ordered sum of 5 prime powers (including 1).at n=40A341134
• a(n) = (3*n-1)*(n^4-18*n^3+179*n^2-582*n+720)/120.at n=17A381193