18820

Appears in sequences

• Expansion of series related to Liouville's Last Theorem: g.f. sum_{t>0} (-1)^(t+1) *x^(t*(t+1)/2) / ( (1-x^t)^5 *product_{i=1..t} (1-x^i) ).at n=17A059822
• Numbers n such that 3*2^(n-1) - 1 is prime.at n=34A091997
• Number of partitions of an n-set without blocks of size 2.at n=10A097514
• Triangle read by rows: T(n,k) is the number of set partitions of the set {1,2,...,n} containing k blocks of size 2 (0 <= k <= floor(n/2)).at n=30A124498
• a(n)=floor(3*n^2*(2+sqrt(3))).at n=40A172526
• Numbers m such that m^2 + 3^k is prime for k = 1, 2, 3.at n=28A177173
• Numbers n such that there is no square n-gonal number greater than 1.at n=24A188896
• Number of (n+2)X(3+2) 0..3 arrays with every 3X3 subblock row, column, diagonal and antidiagonal sum not equal to 0 1 3 6 or 7.at n=4A252316
• Number of (n+2)X(5+2) 0..3 arrays with every 3X3 subblock row, column, diagonal and antidiagonal sum not equal to 0 1 3 6 or 7.at n=2A252318
• T(n,k)=Number of (n+2)X(k+2) 0..3 arrays with every 3X3 subblock row, column, diagonal and antidiagonal sum not equal to 0 1 3 6 or 7.at n=23A252321
• T(n,k)=Number of (n+2)X(k+2) 0..3 arrays with every 3X3 subblock row, column, diagonal and antidiagonal sum not equal to 0 1 3 6 or 7.at n=25A252321
• Solution of the complementary equation a(n) = a(n-1) + a(n-2) + b(n)^2, where a(0) = 1, a(1) = 4, b(0) = 2, b(1) = 3, b(2) = 5, and (a(n)) and (b(n)) are increasing complementary sequences.at n=13A296247
• Triangle read by rows: T(w,h) (for w >= h >= 1) is the number of distinct sets of rectangles with integer sides that tile the w X h rectangle.at n=31A349575
• Number of (undirected) cycles in the n-flower graph.at n=6A368191
• a(n) = A086330(prime(n)).at n=42A371035