21849

Appears in sequences

• a(1) = 3; a(n+1) = a(n)-th nonprime, where nonprimes begin at 0.at n=42A025000
• Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 90 ones.at n=19A031858
• Smallest m such that A065623(m) = n.at n=41A065624
• a(0) = 3, a(1) = 5, a(2) = 1, and a(n) = (2^(1 + n) - 11*(-1)^n)/3 for n > 2.at n=15A115335
• a(n) = (4^n + 11)/3.at n=8A163868
• Total number of ON cells in the "Ulam-Warburton" two-dimensional cellular automaton of A147562 after A048645(n) generations.at n=29A255264
• Right edge of triangle A297497.at n=13A297498
• a(n) + a(n+1) = 2^n for n >= 0 with a(0) = 4.at n=16A352692
• Coefficients in the power series A(x) such that: A(x)^4 = Sum_{n=-oo..+oo} x^n * (1 - x^(n+1))^(n+1) * A(x)^n.at n=6A357204