49727

Properties

Appears in sequences

• a(n) = s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n+1-k), where k = [ (n+1)/2 ], s = (F(2), F(3), ...), t = (primes).at n=25A024597
• a(n) = s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n-k+1), where k = [ n/2 ], s = (F(2), F(3), F(4), ...), t = (primes).at n=24A025111
• Numerator of Sum_{k=1..n} 1/phi(k).at n=40A028415
• Numerators of continued fraction convergents to sqrt(221).at n=7A041412
• Primes of form p^2 - 2, where p is prime.at n=21A049002
• Primes p of form q^k-2 where q is also a prime and k > 1.at n=30A053705
• A Chebyshev T-sequence with Diophantine property.at n=4A078365
• Prime factors of solutions to 24^n == 1 (mod n).at n=3A087807
• Positions of records in A064097.at n=25A105017
• 2*JacobiSymbol(p,5) mod p^2 for p=prime(n).at n=47A113651
• (Product of successive primes minus 2) divided by 7 is prime.at n=1A125502
• Numbers k such that k and k^2 use only the digits 2, 4, 5, 7 and 9.at n=13A137098
• Primes p such that none of p-2, p-1, p+1, and p+2 is squarefree.at n=24A153215
• Primes p such that the differences between p and the closest squares surrounding p are primes.at n=26A163848
• Primes of the form p^q - q, where p and q are primes.at n=23A182474
• Fajtlowicz p-primes.at n=45A185955
• Primes that are arithmetical average of 100 consecutive primes.at n=17A217985
• Smaller of Fermi-Dirac twin primes (A229064) which are not the smaller of twin primes (A001359).at n=27A229500
• The set S of primes q satisfying certain conditions (see Müller, 2010 for precise definition).at n=10A275739
• a(n) = n^4 + 8*n^3 + 20*n^2 + 16*n + 2.at n=13A304725