20967

Appears in sequences

• Numbers k such that sigma(sigma(k)-k) = phi(k).at n=12A074875
• Numbers k such that k and 5*k, taken together, are pandigital.at n=15A115925
• a(n) = 25*n^2 - 2*n.at n=28A154376
• Numbers k such that A(k+1) = A(k) + 1, where A() = A005101() are the abundant numbers.at n=22A169822
• Expansion of phi(-x^6) / f(-x) in powers of x where phi(), f() are Ramanujan theta functions.at n=43A271661
• a(n) = floor( (4 + sqrt(11))^n ).at n=5A279269
• Coefficient of x^n in the expansion of ( (1+x+x^3)^3 / (1+x) )^n.at n=7A372372