18040

Appears in sequences

• Alkane (or paraffin) numbers l(7,n).at n=28A005994
• Expansion of 1/(1-x^5-x^6-x^7-x^8-x^9-x^10-x^11-x^12-x^13-x^14-x^15).at n=43A017846
• Coordination sequence for lattice D*_4 (with edges defined by l_1 norm = 1).at n=15A035471
• Number of partitions of n into parts not of the form 9k, 9k+2 or 9k-2. Also number of partitions with 1 part of size 1 and differences between parts at distance 3 are greater than 1.at n=49A035941
• Numbers k such that k+1, k^2+1 and k^4+1 are primes.at n=38A070325
• a(n) = n*(n+1)*(2*n^2+1)/6.at n=15A071238
• n+phi(n)+phi(phi(n)) is a cube.at n=15A116042
• Numbers k such that k+1, k+3, k+7 and k+9 are all primes.at n=16A125855
• Numbers k such that k^2 divides 9^k - 1.at n=37A127101
• Triangle read by rows: expansion of p(x,n)=If[n == 0, 1, (x + 1)^n + 2^(n-1)*Sum[Binomial[n-m, m]*x^m*(1 + x^(n - 2*m)), {m, 1, n - 1}]].at n=58A146772
• Number of different fixed (possibly) disconnected trominoes bounded (not necessarily tightly) by an n*n square.at n=10A162673
• a(n) = 11*n*(n+1).at n=40A164136
• Number of -n..n arrays x(0..3) of 4 elements with zero sum, and adjacent elements not equal modulo three (with -1 modulo 3 = 2).at n=21A199911
• Number of n-element subsets of [n+4] having an even sum.at n=28A282080
• Numbers n such that A002088(n) < 3n^2/Pi^2.at n=32A285022
• Indices of primes in A000712.at n=22A285217