41943040

Appears in sequences

• a(n) = 10*4^n.at n=11A002066
• a(n) = 5 * 2^n.at n=23A020714
• a(n) = (9*2^n + (-2)^n)/4 for n>0.at n=23A056486
• a(n) = n*2^n - 2^n = 2^n*(n-1).at n=20A058922
• Let P(k,X) = 4^k*Product_{i=1..k} (X - cos(Pi*i/k)) (which is a polynomial with integer coefficients). Sequence gives maximum absolute values of coefficients of P(n,X).at n=11A075614
• Expansion of g.f.: (1+x^2)/(1-2*x).at n=25A084215
• Number of subsets of {1, ..., n} containing exactly one twin prime pair.at n=31A089882
• Number of subsets of {1,.., n} containing exactly one square.at n=27A089889
• Number of subsets of {1,.., n} containing exactly two squares.at n=26A089890
• Expansion of (1-4x+24x^2)/((1-4x)(1+4x)).at n=12A091104
• Smallest number beginning with 4 and having exactly n prime divisors counted with multiplicity.at n=23A106424
• Least n-almost prime of the form semiprime + 1.at n=23A128665
• a(n) = n*2^(floor(n/2)).at n=40A132344
• Binomial transform of A010685.at n=24A146523
• Number of binary strings of length n with equal numbers of 001 and 100 substrings.at n=26A164143
• Inverse binomial transform of A166517.at n=25A166577
• Numbers k such that the sum of digits of k equals the concatenation of the distinct prime divisors of k.at n=10A212667
• G.f. satisfies: A(x) = exp( Sum_{n>=1} [Sum_{k=0..2*n} T(n,k)^2 * x^k] / A(x)^n * x^n/n ), where T(n,k) is the coefficient of x^k in (1 + x + 2*x^2)^n.at n=42A251687
• a(1) = 2, a(2) = 3; thereafter a(n) is the sum of all the previous terms.at n=25A257113
• Encoded symmetrical antidiagonal square binary matrices with either 1 or 2 ones.at n=13A261819