21577

Properties

Appears in sequences

• Coordination sequence for sigma-CrFe, Position Xd.at n=37A009959
• Numbers k such that the continued fraction for sqrt(k) has odd period and if the last term of the periodic part is deleted then there are a pair of central terms both equal to 10.at n=29A031423
• Primes followed by a [10,2,10] prime difference pattern of A001223.at n=21A052376
• Fifth term of weak prime sextet: p(m-3)-p(m-4) < p(m-2)-p(m-3) < p(m-1)-p(m-2) < p(m)-p(m-1) < p(m+1)-p(m).at n=7A054832
• Primes p beginning consecutive prime-difference pattern as follows: p, (10, 2, 10, 2, 10), p+34.at n=1A067140
• Primes of the form (n^2+1)/26.at n=21A208292
• Values k(i) such that k(i) + k(i+3) = k(i+1) + k(i+2), where k(i) is A022885(i).at n=12A235725
• Number of compositions of n with exactly four descents.at n=6A241629
• Initial prime of 4 primes in arithmetic progression with difference 12.at n=42A248085
• Primes of the form 7*k^2 + 7*k + 17.at n=43A256374
• Primes of form n^2 + 20736.at n=1A256840
• Prime numbers such that sum of digits in base 8 equals product of digits in base 8.at n=16A264576
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 195", based on the 5-celled von Neumann neighborhood.at n=32A270691
• Smallest primes of 4 X 4 semimagic squares formed from consecutive primes.at n=37A270865
• Numbers having in binary representation more zeros than their squares.at n=4A293655
• Number of nX4 0..1 arrays with each 1 adjacent to 2 or 3 king-move neighboring 1s.at n=5A295981
• Number of n X 6 0..1 arrays with each 1 adjacent to 2 or 3 king-move neighboring 1's.at n=3A295983
• T(n,k)=Number of nXk 0..1 arrays with each 1 adjacent to 2 or 3 king-move neighboring 1s.at n=39A295985
• T(n,k)=Number of nXk 0..1 arrays with each 1 adjacent to 2 or 3 king-move neighboring 1s.at n=41A295985
• Primes p such that Sum_{k=PreviousPrime(p)..p} d(k) = Sum_{k=p..NextPrime(p)} d(k), where d(k) is the number of divisors function A000005.at n=24A353552