18312

Appears in sequences

• Rounded value of n*L_n(-1) where L is the Laguerre polynomial.at n=21A070070
• Matrix inverse of A103247, so that T(n,k) = C(n,k)*A010842(n-k), read by rows.at n=30A107056
• Number of primes between (prime(n + 1))^Pi and (prime(n))^Pi.at n=34A137380
• Number of nondecreasing arrangements of 7 numbers x(i) in -(n+5)..(n+5) with the sum of sign(x(i))*2^|x(i)| zero.at n=18A187991
• Expansion of Sum_{k>=0} x^((k+1)^2)/(1-x)^k.at n=56A236310
• Inverse permutation of A064364, when seen as flattened list.at n=58A257815
• Practical numbers m with m-1 and m+1 both prime, and prime(m)-1 and prime(m)+1 both practical.at n=7A257922
• Numbers n such that the decimal digits of n-phi(n) are a permutation of those of n.at n=35A273799
• Number of 7-digit numbers whose sum of digits is n.at n=12A278969
• Number of 7-digit numbers whose sum of digits is n.at n=50A278969
• Complete list of solutions to y^2 + y = x^3 - 525x + 10156 with y > 0; sequence gives positive y values.at n=13A317053
• a(n) is the number of regions formed by n-secting the angles of a heptagon.at n=41A335757
• Averages k of twin primes such that the sum (with multiplicity) of prime factors of k-1, k and k+1 is prime.at n=39A340060
• E.g.f.: Product_{k>=1} 1 / (1 - x^k)^(tan(x)/k).at n=7A347897
• Irregular table read by rows: T(n,k) is the number of k-sided polygons formed, for k>=3, in a square when straight line segments connect the n+1 points along each edge that divide it into n equal parts to the n+1 points on the edge on the opposite side of the square.at n=46A355841
• E.g.f. satisfies A(x) = 1/(1 + A(x) * log(1 - x))^3.at n=4A377446
• a(n) = Sum_{k=0..n} binomial(n+3*k,k).at n=5A389239