4190209
domain: N
Appears in sequences
- Generalized Euler phi function (for p=2).at n=22A003473
- a(n) = (2^n - 1)^2.at n=10A060867
- a(n) = A073145(n)^2.at n=31A073702
- Expansion of (1 + 2*x^2)/((1 + x)*(1 - 2*x)*(1 - 2*x^2)).at n=21A085903
- Smallest square k == 1 (mod some n-th power), k > 1.at n=11A088037
- a(2*n) = -(2^(2*n+1) + 1), a(2*n+1) = (2^(n+1) - (-1)^n)^2.at n=21A105951
- a(n) = 1+4^(n+1)-4*(-2)^n.at n=10A171590
- (2^p-1)^2 where p is prime.at n=4A174744
- a(n) = (1-2*n^2)^2.at n=32A239607
- Numbers k with the property that it is possible to write the base 2 expansion of k as concat(a_2,b_2), with a_2>0 and b_2>0 such that, converting a_2 and b_2 to base 10 as a and b, we have (a+b)^2 = k.at n=36A258844
- Number of active (ON, black) cells at stage 2^n-1 of the two-dimensional cellular automaton defined by "Rule 5", based on the 5-celled von Neumann neighborhood.at n=10A270007
- Number of active (ON, black) cells at stage 2^n-1 of the two-dimensional cellular automaton defined by "Rule 73", based on the 5-celled von Neumann neighborhood.at n=10A270088
- Number of active (ON, black) cells at stage 2^n-1 of the two-dimensional cellular automaton defined by "Rule 89", based on the 5-celled von Neumann neighborhood.at n=10A270130
- Number of active (ON, black) cells at stage 2^n-1 of the two-dimensional cellular automaton defined by "Rule 659", based on the 5-celled von Neumann neighborhood.at n=10A273385
- Number of active (ON, black) cells at stage 2^n-1 of the two-dimensional cellular automaton defined by "Rule 913", based on the 5-celled von Neumann neighborhood.at n=10A273767
- Number of active (ON, black) cells at stage 2^n-1 of the two-dimensional cellular automaton defined by "Rule 969", based on the 5-celled von Neumann neighborhood.at n=10A273848
- Number of holes in a sheet of paper when you fold it n times and cut off the four corners.at n=22A274230
- a(2n) = A060867(n+1), a(2n+1) = A092440(n+1).at n=20A276918
- a(n) is the largest perfect power < 2^n.at n=19A357752
- a(n) is the largest square with n binary digits.at n=19A357754