21936

Appears in sequences

• Numbers k such that 225*2^k+1 is prime.at n=39A032489
• a(n)=Sum{a(k): k=0,1,2,...,n-3,n-1}; a(n-2) is not a summand; 2 initial terms required.at n=18A049854
• a(n)! begins with 2^n.at n=15A059449
• a(n) = 2*a(n-1) + 2*a(n-2) - 2*a(n-3) with a(0)=3, a(1)=2, a(3)=8.at n=11A107300
• Transform of the finite sequence (1, 0, -1) by the T_{1,0} transformation (see link).at n=12A159336
• a(n) = a(n-2)+a(n-3) with a(1)=2 a(2)=1 a(3)=0.at n=37A276276
• Triangle T(n,k) read by rows: coefficients of polynomials P_n(t) defined in Formula section.at n=32A286800
• Number of solutions to +-1 +- 5 +- 12 +- ... +- n*(3*n-1)/2 = 0.at n=26A292474
• Number of nX4 0..1 arrays with every element equal to 0, 1, 2 or 4 king-move adjacent elements, with upper left element zero.at n=14A297885
• Positive integers that have exactly ten representations of the form 1 + p1 * (1 + p2* ... * (1 + p_j)...), where [p1, ..., p_j] is a (possibly empty) list of distinct primes.at n=20A317400
• Number of odd-length twice-partitions of n into odd-length partitions.at n=20A358834