20295

Appears in sequences

• Fibonacci sequence beginning 0, 3.at n=20A022086
• Write 1, 2, 3, 4, ... counterclockwise in a hexagonal spiral around 0 starting left down, then a(n) is the sequence found by reading from 0 in the vertical upward direction.at n=41A063436
• a(n) = 3*Fibonacci(2*n) + 0^n.at n=10A097134
• a(0) = 1; for n>0, a(n) = 3*Fibonacci(n).at n=20A097135
• Expansion of g.f. (3-x)*(1+3*x+x^2)/((1-x-x^2)*(1+x-x^2)).at n=18A099256
• a(n) = n*(n+13)*(n+14)/6.at n=41A111144
• Expansion of c(x^2-x^3), c(x) the g.f. of A000108.at n=18A115399
• G.f.: x^2*(3+3*x-2*x^2)/ ( (x^2-x-1) * (x^2+x-1)).at n=20A122012
• Row sums of A131325.at n=19A131326
• Sixth degree product sequence: a(n) = product( 1 +4*cos(k*Pi/n)^2 +16*cos(k*Pi/n)^4 +64*cos(k*Pi/n)^6, k=1..(n-1)/2 ).at n=10A152116
• A sixth degree product form sequence: a(n)=Product[(1 + 4*Sin[k*Pi/n]^2 + 16*Sin[k*Pi/n]^4 + 64*Sin[k*Pi/n]^6), {k, 1, Floor[(n - 1)/2]}].at n=10A152143
• Numbers k such that sigma(tau(k)) equals the sum of distinct primes dividing k.at n=40A173325
• Denominator of a-sequence for Sheffer triangle A060081.at n=40A176727
• a(n) = Sum_{i=0..n} digsum_4(i)^4, where digsum_4(i) = A053737(i).at n=44A231667
• Numbers n such that n^8+8 and n^8-8 are prime.at n=20A239503
• a(n) = gcd(Sum_{k=1...n} F(k), Product{j=1...n} F(j)), where F(k) is the k-th Fibonacci number.at n=39A239740
• Number of partitions p of n such that m(p) <= m(c(p)), where m = maximal multiplicity of parts, and c = conjugate.at n=39A240727
• a(n) is the least positive integer k such that 2^n-1 and k^n-1 are relatively prime.at n=39A260119
• Numbers equidistant from twin prime pairs that are also equidistant from numbers equidistant from twin prime pairs.at n=25A260517
• Positions of 3's in A264977; positions of 6's in A277330.at n=39A277713