20717

Properties

Appears in sequences

• Numbers k such that the continued fraction for sqrt(k) has period 83.at n=17A020422
• Primes p such that p - 6 is a product of two consecutive primes.at n=16A098061
• Indices of primes in sequence defined by A(0) = 43, A(n) = 10*A(n-1) + 63 for n > 0.at n=16A101739
• Primes p such that p + 2 and p^2 + 2^2 are primes.at n=35A107312
• Lesser of twin primes p such that 6*p+1 is greater of twin primes.at n=12A176131
• Number of (n+3)X11 binary arrays with every 4X4 subblock commuting with each horizontal and vertical neighbor 4X4 subblock.at n=9A188104
• Reversion of x-x^2-x^3-x^4-x^5-x^6.at n=8A191243
• Primes p with A047967(p) also prime.at n=16A236418
• Primes p such that p*q*r + 6 and p*q*r - 6 are primes where q and r are the next two primes after p.at n=16A240715
• Number of n X n 0..3 arrays with no element equal to one plus the sum of elements to its left or zero plus the sum of the elements above it or one plus the sum of the elements diagonally to its northwest or one plus the sum of the elements antidiagonally to its northeast, modulo 4.at n=4A241277
• Number of nX5 0..3 arrays with no element equal to one plus the sum of elements to its left or zero plus the sum of elements above it or one plus the sum of the elements diagonally to its northwest or one plus the sum of the elements antidiagonally to its northeast, modulo 4.at n=4A241281
• T(n,k)=Number of nXk 0..3 arrays with no element equal to one plus the sum of elements to its left or zero plus the sum of the elements above it or one plus the sum of the elements diagonally to its northwest or one plus the sum of the elements antidiagonally to its northeast, modulo 4.at n=40A241283
• Number of 5Xn 0..3 arrays with no element equal to one plus the sum of elements to its left or zero plus the sum of the elements above it or one plus the sum of the elements diagonally to its northwest or one plus the sum of the elements antidiagonally to its northeast, modulo 4.at n=4A241287
• Initial members of prime quadruples (n, n+2, n+54, n+56).at n=22A248661
• Subtract 1 from the terms of A256407.at n=35A256410
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 673", based on the 5-celled von Neumann neighborhood.at n=24A273406
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 961", based on the 5-celled von Neumann neighborhood.at n=24A273833
• Let F(g,p) be the frequency of g up to prime nextprime(p+1). Primes p such that F(2,p) = F(4,p) and g = 2 or 4.at n=32A274122
• 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=13A295013
• Number of integer partitions of 2n without a nonempty initial consecutive subsequence summing to n.at n=19A362051