19007

Appears in sequences

• a(1) = 1; a(n) = a(n-1) + sigma(a(n-1)) where sigma(k) = sum of the divisors of k.at n=13A081973
• Irregular array where row n is the positive integers which divide the sum of all previous rows. a(1,1)=1.at n=41A119763
• Row sums of triangle A143102.at n=37A143103
• a(n) = 576*n - 1.at n=32A158372
• a(n) = abs(a(n-1) - 3*a(n-2)) with a(1)=a(2)=1.at n=22A192263
• Expansion of x*(1+x)/(1-x-2*x^2-2*x^3-x^4).at n=12A210460
• A bisection of A183168.at n=39A215933
• Number of (n+1) X (1+1) 0..1 arrays with no 2 X 2 subblock having zero or two 1's.at n=9A251212
• a(n) = (n+1)^3 - n^2.at n=26A261893
• Expansion of Product_{k>=1} 1/(1 - x^(2*k - 1))^(k^2).at n=19A294750
• Anagrasum integers: integers N that exactly reproduce their set of digits when we form the set of sums of pairs of adjacent digits.at n=42A296521
• Expansion of (1 + x + x^3)/(1 - x^2 - 2*x^4 - 2*x^6 + x^8).at n=25A363958
• Semiprimes k such that k+2 and k+6 are primes and k+4 and k+8 are all semiprimes.at n=11A392186