20719

Properties

Appears in sequences

• Expansion of (3-2*x-3*x^2-4*x^3)/(1-3*x+x^2+x^3+x^4).at n=11A024876
• Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 92 ones.at n=12A031860
• Numbers k such that 249*2^k+1 is prime.at n=48A032501
• Denominators of continued fraction convergents to sqrt(828).at n=9A042599
• Primes p such that p, p+12, p+24 are consecutive primes.at n=20A052188
• Indices of primes in sequence defined by A(0) = 99, A(n) = 10*A(n-1) - 1 for n > 0.at n=8A056266
• Primes p such that x^36 = 2 has no solution mod p, but x^12 = 2 has a solution mod p.at n=26A059668
• Prime numbers occurring at integer Pythagorean distance (radius) from 1 in Ulam square prime-spiral. Primes on axes are excluded.at n=31A078765
• Primes in the sequence A003294 of certain fourth powers bases.at n=14A134820
• Largest primes of 'a' consecutive primes whose sum is a prime in A152471.at n=40A152472
• Triangle T(n, k, m) = (m*(n-k) + 1)*T(n-1, k-1, m) + (m*k + 1)*T(n-1, k, m) + m*k*(n-k)*T(n-2, k-1, m) with T(n, 0, m) = T(n, n, m) = 1 and m = 2, read by rows.at n=23A157148
• Triangle T(n, k, m) = (m*(n-k) + 1)*T(n-1, k-1, m) + (m*k + 1)*T(n-1, k, m) + m*k*(n-k)*T(n-2, k-1, m) with T(n, 0, m) = T(n, n, m) = 1 and m = 2, read by rows.at n=25A157148
• Numbers m such that m^2 is an anagram of a Fibonacci number.at n=17A162391
• Totally multiplicative sequence with a(p) = a(p-1) + 9 for prime p.at n=30A166706
• Primes of the form x^3 + 2*y^3, with nonnegative x and y.at n=35A219559
• Fifth prime p such that (p+n)^2+n is prime but (p+j)^2+j is not prime for all 0<j<n.at n=22A238677
• Primes equal to the sum of both two and three successive semiprimes.at n=17A255897
• Prime time primes (of the form HMMSS with primes H < 24 and MM, SS < 60) such that the corresponding number of seconds after midnight is also prime.at n=4A295000
• Numbers of the form HMMSS with primes H < 24 and MM, SS < 60, for which the number of seconds after midnight, 3600*H+60*MM+SS, is also prime.at n=16A295011
• 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=14A295013