75920

Appears in sequences

• Expansion of (5 + 6*x + 3*x^2 - 2*x^3) / (1 - 2*x - 2*x^2 - 2*x^3 + x^4) in powers of x.at n=9A071101
• a(0)=1; a(n) = sigma_2(n) + sigma_3(n).at n=40A092344
• a(n) = 4*a(n-1) - 4*a(n-2) + 3*a(n-3).at n=11A099215
• Small-number statistic from the enumeration of domino tilings of a 3-pillow of order n.at n=21A112835
• Define K(n) = Integral_{t=-1..1} (t^(2n)*(1-t^2)^(2n)/(1+it)^(3n+1))dt, and write K(n) = a(n)*Pi - b(n)/c(n) where a(n), b(n), c(n) are positive integers; the sequence gives a(n).at n=2A123178
• a(n) = 2*a(n-1) + 2*a(n-2) + 2*a(n-3) - a(n-4); a(0)=0, a(1)=1, a(2)=2, a(3)=5.at n=12A138573
• Positive integers with the property that if the base-3 representation is reversed the result is twice the original number.at n=12A173951
• Expansion of x * (1 + x) * (1 - x^2) * (1 + x^3) / (1 - 2*x^2 - 2*x^4 - 2*x^6 + x^8) in powers of x.at n=24A206625
• Numbers k such that (3^ord(3, k) - 1)/k is prime, where ord(3, k) is the multiplicative order of 3 (mod k).at n=33A297363
• Integers k such that k*2^k + 3 is prime.at n=20A382094