19749

Appears in sequences

• T(2n-1,n-1), T given by A026907.at n=5A026912
• T(n,[ n/2 ]), T given by A026907.at n=11A026914
• Number of partitions of n into distinct partition numbers.at n=26A068006
• a(1) = a(2) = a(3) = a(4) = 1. For n>= 5, a(n) = a(n-1)*a(n-4) + a(n-2)*a(n-3).at n=11A111289
• G.f.: A(x) = exp( Sum_{n>=1} [ Sum_{k>=1} sigma(k,n)*x^k ]^n/n ).at n=7A159595
• Ascending sequence of numbers such that the sum of any two distinct elements (even + odd) is a prime number.at n=40A180743
• Arithmetic derivative of central binomial coefficients, cf. A000984.at n=8A258290
• Numbers k such that (43*10^k + 101)/9 is prime.at n=20A294569
• Number of equivalence classes of 132-avoiding permutations of [n], where two permutations are equivalent if they have the same set of pure descents.at n=12A295704
• Number of integer partitions of n whose Heinz number (product of primes of parts) is divisible by their sum of primes of parts.at n=47A330953
• a(n) = Sum_{k=0..n} k^(k*n).at n=3A349886
• Nonprime numbers k of the form 4*m+1 such that Sum_{j=0..k-1} 2^j * binomial(3*j, j) == 1 (mod k).at n=30A373747