20261

Properties

Appears in sequences

• Discriminants of real quadratic fields with class number 1 and related continued fraction period length of 17.at n=24A050966
• Smallest prime divisor of n-th primorial + (n+1)-st prime.at n=29A065315
• Magnanimous primes: primes with the property that inserting a "+" in any place between two digits yields a sum which is prime.at n=46A089392
• Smallest n-digit magnanimous prime (A089392), or 0 if there is no such prime with n digits.at n=4A089393
• Round(1000*x), where x is the solution to x = 3^(n-x).at n=23A103537
• Primes and their indices such that when their respective SOD's are both prime, the SOD of the index is the nextprime of the prime SOD.at n=31A117458
• Primes congruent to 24 mod 59.at n=36A142751
• Primes congruent to 9 mod 61.at n=38A142807
• Primes p such that continued fraction of (1 + sqrt(p))/2 has period 17 : primes in A146340.at n=31A146362
• Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, -1), (-1, 1, 1), (0, 1, 1), (1, 0, 1), (1, 1, 0)}.at n=7A151155
• a(n) = floor(1/{(10+n^4)^(1/4)}), where {}=fractional part.at n=36A184634
• G.f. satisfies: A(x) = exp( Sum_{n>=1} (1+x)^n * A(x^n) * x^n/n ).at n=10A199103
• Prime(n) such that prime(3n) - prime(2n) - prime(n) is a perfect cube.at n=12A224863
• Primes whose base-7 representation also is the base-4 representation of a prime.at n=51A235617
• Prime time primes on 6-digit clocks, second definition: primes of the form HMMSS where H, MM, SS are primes, H < 24, MM and SS < 60.at n=2A295013
• Number of nX2 0..1 arrays with every element unequal to 0, 2, 3 or 4 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.at n=12A318039
• Number of strict compositions of n whose non-adjacent parts are strictly decreasing.at n=45A333150
• Primes p such that 2*p^2-q^2 and 2*q^2-p^2 are prime, where q is the next prime after p.at n=40A338836
• Prime numbersat n=2290