270532608

Appears in sequences

• S(n; 2,0) where S(n; t,s) is the number of length n 4-ary strings whose digits sum to t mod 4 and whose sum of products of all pairs of digits sum to s mod 4.at n=15A068789
• Number of strings over Z_4 of length n with trace 2 and subtrace 2.at n=15A068790
• Second differences of Mersenne numbers A001348, divided by 4.at n=8A139243
• Number of solutions to Sum_{i=1..n} x_i^2 == 0 (mod 4) with x_i in 0..3.at n=14A228920
• a(n) = 2^(n*(n-1)/2) + 2^(n*(n+1)/2) for n > 0, with a(0) = 1.at n=7A337949
• a(n) = n^7 * Product_{p|n, p prime} (1 + 1/p^7).at n=15A351302