19864

Appears in sequences

• Theta series of A2[hole]^4.at n=36A033690
• G.f.: 3/(1 + 2*sqrt(1-12*x)).at n=5A035610
• Duplicate of A035610.at n=5A089023
• Expansion of c(3*x^2)/(1-x*c(3*x^2)), c(x) the g.f. of A000108.at n=10A128386
• a(0)=0, a(1)=1, a(2)=4, a(3)=13; thereafter a(n+3)=4*a(n+2)-4*a(n+1)+2*a(n) for n>=1.at n=10A159036
• Square array A(n,k) by antidiagonals. A(n,k) is the number of length 2n k-ary words (n,k>=0) that can be built by repeatedly inserting doublets into the initially empty word.at n=50A183135
• Cogrowth function of the group Baumslag-Solitar(5,5).at n=5A229647
• Cogrowth function of the group Baumslag-Solitar(6,6).at n=5A229648
• Cogrowth function of the group Baumslag-Solitar(7,7).at n=5A229649
• Cogrowth function of the group Baumslag-Solitar(8,8).at n=5A229650
• Cogrowth function of the group Baumslag-Solitar(9,9).at n=5A229651
• Cogrowth function of the group Baumslag-Solitar(10,10).at n=5A229652
• Sum of the squarefree parts of the partitions of n into 5 parts.at n=37A309480
• Sum of the even parts in the partitions of n into 7 parts.at n=34A309626
• Numbers k such that k and k+2 are both infinitary practical numbers (A334901).at n=39A334903
• Cogrowth sequence of the Brin-Navas group B.at n=5A359705