19818

Appears in sequences

• Number of partitions of n into parts not of the form 13k, 13k+5 or 13k-5. Also number of partitions with at most 4 parts of size 1 and differences between parts at distance 5 are greater than 1.at n=41A035953
• Numbers k such that k^4 == 1 (mod 5^5).at n=25A056102
• Sum of the cubes of A058182.at n=7A087417
• Number of ways to place 7 nonattacking amazons (superqueens) on a 7 X n board.at n=12A174646
• Numbers n such that n^2 + 1 is divisible by a 5th power.at n=12A218564
• Expansion of phi(-x^5) * f(x^2, x^8) / psi(-x)^2 in powers of x where phi, psi, f(,) are Ramanujan theta functions.at n=26A259392
• Coefficients in the expansion of ([s] + [2s]x + [3s]x^2 + ...)/([r] + [2r]x + [3r]x^2 + ...); [ ] = floor, r = sqrt(2), s = sqrt(3).at n=46A279628
• Expansion of Sum_{i>=0} x^(2^i)/(1 - x^(2^i)) / Product_{j>=0} (1 - x^(2^j)).at n=51A281688
• a(n) is the smallest number d if the point (d,d) is shared by exactly n different Dyck paths in the main diagonal of the diagram of the symmetries of sigma described in A237593.at n=18A282197
• Solution of the complementary equation a(n) = a(n-1) + a(n-2) + b(n-2)*b(n-1)*b(n), where a(0) = 1, a(1) = 2, b(0) = 3, b(1) = 4, b(2) = 5, and (a(n)) and (b(n)) are increasing complementary sequences.at n=10A296278
• The sum of the first n terms of the sequence is the concatenation of the first n digits of the sequence, and a(1) = 2.at n=4A299865
• Main diagonal of array in A358304, divided by 2.at n=36A358307
• Expansion of Sum_{1<=i<=j<=k} q^(i+j+k)/( (1-q^i)*(1-q^j)*(1-q^k) )^2.at n=14A374930