24121

Properties

Appears in sequences

• a(n) = 4*a(n-1) + 9*a(n-2).at n=7A015533
• Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 86 ones.at n=32A031854
• Denominators of continued fraction convergents to sqrt(372).at n=6A041705
• Numerator of Sum_{i=1..n} 1/C(2*i,i).at n=7A112097
• Numerators of 2*Sum_{k=1..n} 1/binomial(2*k,k), n >= 1.at n=6A130545
• Primes congruent to 26 mod 61.at n=38A142824
• a(n) = 15n^2 + 3n + 1.at n=39A165806
• Primes p such that 5*p+2, 7*p+4 and 11*p+6 are also prime.at n=27A173880
• The Riemann primes of the psi type and index 1.at n=38A197185
• a(n) is the first prime index where the gap between R(n), Riemann's prime counting function, and Pi(n), the exact prime counting function, is greater than n.at n=10A226473
• a(n) = Sum_{i=0..n} digsum_9(i)^4, where digsum_9(i) = A053830(i).at n=18A231687
• a(0)=0, a(1)=1, a(n) = min{4 a(k) + (4^(n-k)-1)/3, k=0..(n-1)} for n>=2.at n=25A259665
• Primes having only {1, 2, 4} as digits.at n=27A260267
• Numbers k such that (73*10^k + 143)/9 is prime.at n=25A272193
• Primes equal to an octagonal number plus 1.at n=18A285792
• Prime numbers p such that 3*p - 2 is the square of a prime number.at n=17A289135
• Positive numbers for which the product of digits is equal to the power tower of digits (right-associative).at n=49A321990
• Prime numbers congruent to 49 or 121 modulo 240 representable by x^2 + 960*y^2.at n=34A325090
• Number of integer partitions of n with exactly two distinct multiplicities.at n=45A325243
• Primes which, when added to their reversals, produce palindromic primes.at n=32A342681