22648

Appears in sequences

• Composite numbers k such that sigma(k)*(phi(k) + 2) is a square.at n=30A065655
• Least m such that both p|m and p+2|m+2 for twin prime pairs (p,p+2) (p=A001359).at n=11A097972
• Numbers k such that 4*10^k - 11 is prime.at n=18A102738
• a(n) = prime(n)*(prime(n+1) + 1).at n=34A123134
• a(n) = (7*n+2)*(7*n+5) = 49*n^2 + 49*n + 10.at n=21A177060
• Integers k that have the property that there exists an integer x with n+1 digits, such that 1 <= k/x < 2 and k/x = 1 + (x-10^n)/(10^n-1), i.e., the same digits appear in the denominator and in the recurring decimal.at n=14A288782
• The indices where A354606(n) = 1.at n=34A355606
• G.f. A(x) satisfies A(x) = 1/(1 - x) + x*A(x)^3/(1 - x)^2.at n=6A366177
• Triangle read by rows: the almost-Riordan array ( 1/(1-x) | 2/((1-x)*(1+x+sqrt(5*x^2-6*x+1))), (1-3*x-sqrt(5*x^2-6*x+1))/(2x) ).at n=48A373746