54251

Properties

Appears in sequences

• Expansion of (1+2*x)/(1-6*x+x^2).at n=6A054488
• Combined Diophantine Chebyshev sequences A054488 and A077413.at n=12A077241
• Primes which are a concatenation of n and prime(n).at n=15A084667
• a(2n) = -A106328(n), a(2n+1) = A054488(n).at n=13A108931
• Number of permutations of length n which avoid the patterns 2134, 3421, 4123.at n=14A116759
• a(n) is the smallest natural number we cannot obtain from n, n+1, n+2, n+3, n+4, n+5, n+6, n+7, n+8 and the operators +, -, *, /, using each number only once.at n=2A143193
• Centered heptagonal prime numbers.at n=28A144974
• Sophie Germain primes in A154939.at n=30A154941
• a(n) = prime(prime(n^2)).at n=26A217623
• Prime(prime(n^3)).at n=8A217625
• a(n) is the smallest n-isolated prime, or a(n)=0 if there are no n-isolated primes.at n=18A218275
• Number of (n+2) X (3+2) 0..3 arrays with every consecutive three elements in every row, column, diagonal and antidiagonal having exactly two distinct values, and new values 0 upwards introduced in row major order.at n=7A253039
• Prime numbersat n=5519