1549681956

Appears in sequences

• Expansion of (1+x)/(1-3*x).at n=19A003946
• a(1)=1, a(2)=2, a(n) = 4*3^(n-3) for n >= 3.at n=20A025579
• a(n) = Sum_{k=0..2n} (k+1) * A025177(n, k).at n=17A027261
• a(n) = Sum_{k=0..m} (k+1) * A026120(n, m-k), where m=0 for n=0,1; m=n for n >= 2.at n=19A027327
• Number of compositions of n into 2*j-1 kinds of j's for all j>=1.at n=20A052156
• Write n in decimal, omit 0's, raise each digit k to k-th power and multiply.at n=29A061510
• Records in A133048.at n=42A133059
• a(n) = (7*3^n - (-3)^n)/6.at n=19A133125
• Numbers that set records in A133500.at n=35A133504
• Spiral tiling numbers.at n=34A137333
• Number of permutations of 2 indistinguishable copies of 1..n arranged in a circle with exactly 1 local maximum.at n=16A159715
• Number of reduced words of length n in Coxeter group on 4 generators S_i with relations (S_i)^2 = (S_i S_j)^20 = I.at n=19A168825
• Number of reduced words of length n in Coxeter group on 4 generators S_i with relations (S_i)^2 = (S_i S_j)^21 = I.at n=19A168873
• Number of reduced words of length n in Coxeter group on 4 generators S_i with relations (S_i)^2 = (S_i S_j)^22 = I.at n=19A168921
• Number of reduced words of length n in Coxeter group on 4 generators S_i with relations (S_i)^2 = (S_i S_j)^23 = I.at n=19A168969
• Number of reduced words of length n in Coxeter group on 4 generators S_i with relations (S_i)^2 = (S_i S_j)^24 = I.at n=19A169017
• Number of reduced words of length n in Coxeter group on 4 generators S_i with relations (S_i)^2 = (S_i S_j)^25 = I.at n=19A169065
• Number of reduced words of length n in Coxeter group on 4 generators S_i with relations (S_i)^2 = (S_i S_j)^26 = I.at n=19A169113
• Number of reduced words of length n in Coxeter group on 4 generators S_i with relations (S_i)^2 = (S_i S_j)^27 = I.at n=19A169161
• Number of reduced words of length n in Coxeter group on 4 generators S_i with relations (S_i)^2 = (S_i S_j)^28 = I.at n=19A169209