67117056

Appears in sequences

• Number of (n-1)-bead black-white reversible strings; also binary grids; also row sums of Losanitsch's triangle A034851; also number of caterpillar graphs on n+2 vertices.at n=27A005418
• Number of types of Boolean functions of n variables under a certain group.at n=12A028402
• Sum of every 4th entry of row n in Pascal's triangle, starting at binomial(n,2).at n=28A038505
• Number of elements of GF(2^n) with trace 0 and subtrace 0.at n=28A038518
• Number of 2n-bead balanced binary strings, rotationally equivalent to complement.at n=26A045654
• Expansion of 2*(1-x-x^2)/((1-2*x)*(1-2*x^2)).at n=26A052957
• a(-1) = 1; for n >= 0, a(n) = 2^n + 4^n = 2^n*(1 + 2^n).at n=14A063376
• Number of words of length 2n in the two letters s and t that reduce to the identity 1 by using the relations ssTT=1, ststSS=1 and ststTT=1, where S and T are the inverses of s and t, respectively (i.e., sS=1 and tT=1). The generators s and t and the three stated relations generate the quaternion group Q4.at n=13A071930
• (4^n+2^n+0^n+(-2)^n)/4.at n=14A083885
• Number of compositions of n with an even number of 1's.at n=28A113979
• a(2n) = a(n) + 2^(2n), a(2n+1) = 2^(2n+1).at n=26A129342
• a(n) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) for n >= 4 starting with a(0) = 1, a(1) = 2, a(2) = 4, and a(3) = 6.at n=27A131885
• a(n) = 2^n + 4^n.at n=13A161168
• Number of binary necklaces of 2n beads for which a cut exists producing a palindrome.at n=26A185376
• Number of degree n polynomials f with all nonzero coefficients equal to 1 such that f(k) is divisible by 4 for all integers k.at n=30A309846
• Table read by antidiagonals: T(n,k) is the number of tilings of the n X k grid up to horizontal and vertical reflections by an asymmetric tile.at n=29A368220
• Table read by antidiagonals: T(n,k) is the number of tilings of the n X k grid up to horizontal and vertical reflections by an asymmetric tile.at n=34A368220
• Oblong numbers of the form 2^k*(2^k - 1) or 2^k*(2^k + 1).at n=25A390325