21071

Appears in sequences

• Expansion of Product_{m>=1} (1 + m*q^m)^7.at n=7A022635
• a(1) = 1; thereafter a(n) is always the smallest integer > a(n-1) not leading to a contradiction, such that any five consecutive digits in the sequence sum up to a prime.at n=36A152605
• Related to Fibonacci numbers, see the Formula section.at n=32A215082
• a(n) = A215082(2*n).at n=16A215108
• a(n) = (n + 1)*(6*n^2 + 15*n + 4)/2.at n=18A269232
• Expansion of (1/(1 - x))*Product_{k>=1} 1/(1 - x^k)^p(k), where p(k) is the number of partitions of k (A000041).at n=14A291552
• a(n) = [x^n] Product_{k>=1} (1 + k*x^k)^n.at n=7A297322
• Number of chiral pairs of color loops of length n with exactly 3 different colors.at n=11A305542