18895

Appears in sequences

• Numbers k such that 2*10^k + 3*R_k is prime, where R_k = 11...1 is the repunit (A002275) of length k.at n=21A056701
• Numbers k such that 7*10^k + 6*R_k + 3 is prime, where R_k = 11...1 is the repunit (A002275) of length k.at n=26A103065
• Total number of largest parts in all partitions of n that contain at least two distinct parts.at n=35A182629
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 5", based on the 5-celled von Neumann neighborhood.at n=29A270008
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 5", based on the 5-celled von Neumann neighborhood.at n=30A270008
• Alternating sum of centered octagonal pyramidal numbers.at n=30A270695
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 261", based on the 5-celled von Neumann neighborhood.at n=29A271062
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 469", based on the 5-celled von Neumann neighborhood.at n=29A272418
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 718", based on the 5-celled von Neumann neighborhood.at n=38A273427
• Complete list of solutions to y^2 + y = x^3 - 525x + 10156; sequence gives x values.at n=20A303615
• Least k > 1 such that k^n is a twin rank (cf. A002822: 6*k^n +- 1 are twin primes).at n=37A326230
• Numbers k such that both k and k+2 are de Polignac numbers (A006285).at n=28A330284
• Least start of a run of exactly n consecutive odd numbers that are all de Polignac numbers (A006285).at n=2A330303
• G.f.: 1/Product_{k>=1} (1 - x^(2*k^2)) * (1 - x^k).at n=30A385011