1782225

Appears in sequences

• Squares of odd pentagonal numbers.at n=15A014769
• Coefficients of power series A(x) consist entirely of squares, where A(x) = A083352(x)^2 + A083352(x) - 1.at n=44A083353
• Squares of pentagonal numbers: a(n) = (1/4)*n^2*(3*n-1)^2.at n=30A100255
• Numbers k such that k^k == 1 (mod sigma(k)).at n=35A181476
• Number of 4Xn 0..1 arrays avoiding 0 0 0 and 0 1 0 horizontally and 0 0 1 and 1 0 0 vertically.at n=7A207742
• Numbers k such that phi(k)^phi(k) == 1 (mod sigma(k)).at n=23A248861
• 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=34A258844