19071

Appears in sequences

• Numbers k such that 13*2^k - 1 is prime.at n=11A001773
• Numbers k such that the largest prime factor of k is equal to the sum of primes dividing k+1 (with repetition).at n=20A071861
• Number of simple chains with n-1 edges strongly embedded in a simple cubic lattice.at n=7A118339
• Polynomial expansion of p(x)=1/(1 - 3 x + 2 x^2 + 2 x^3 - 4 x^4 + 4 x^5 - 2 x^6 - 2 x^7 + 3 x^8 - x^9 - x^17 + 3 x^18 - 2 x^19 - 2 x^20 + 4 x^21 - 4 x^22 + 2 x^23 + 2 x^24 - 3 x^25 + x^26).at n=38A164787
• a(n) = n^3/6 + 3*n^2/4 + 7*n/3 + 7/8 + (-1)^n/8.at n=47A173154
• Numbers k such that k^3 divides 17^(k^2) + 1.at n=20A177817
• Numbers k such that k^2+1 = 2p,(k+1)^2+1 = 5q, (k+2)^2+1 = 10r where p, q, and r are primes.at n=26A181619
• Convolution of A006068 (inverse of Gray code) with itself: a(n) = Sum_{k=1..n+1} A006068(k) * A006068(1+n-k).at n=43A268721
• Expansion of Product_{k>=1} 1 / (1 - Sum_{j>=1} j * x^(j*(2*k - 1))).at n=11A329163
• a(n) = (n - 1) * Sum_{k=2..n} A000010(k).at n=39A385682