27591

Appears in sequences

• Expansion of 1/(1-x^4-x^5-x^6-x^7-x^8-x^9-x^10-x^11-x^12-x^13-x^14).at n=38A017836
• Number of ways to build a contiguous building with n LEGO blocks of size 1 X 4 on top of a fixed block of the same size.at n=2A123782
• Irregular array T(n,k) of the numbers of non-extendable (complete) non-self-adjacent simple paths starting at each of a minimal subset of nodes within a square lattice bounded by rectangles with nodal dimensions n and 6, n >= 2.at n=39A214025
• Irregular array T(n,k) of the numbers of non-extendable (complete) non-self-adjacent simple paths starting at each of a minimal subset of nodes within a square lattice bounded by rectangles with nodal dimensions n and 7, n >= 2.at n=34A214037
• Expansion of Sum_{i>=0} x^(2^i) / (1 - Sum_{j>=0} x^(2^j))^2.at n=14A281811
• Number of nX5 0..1 arrays with every element equal to 1, 2, 4, 6 or 7 king-move adjacent elements, with upper left element zero.at n=10A298657
• Numbers k such that 3*4^k+1 is prime.at n=20A326655
• a(n) = Sum_{k=1..n} sigma(k)*sigma(2*k), where sigma(n) = A000203(n) is the sum of the divisors of n.at n=22A347108