129127041
domain: N
Appears in sequences
- 2-hyperperfect numbers: n = 2*(sigma(n) - n - 1) + 1.at n=4A007593
- Number of strings over Z_3 of length n with trace 0 and subtrace 0.at n=18A073947
- Number of strings over Z_3 of length n with trace 1 and subtrace 0.at n=18A073950
- Number of elements of GF(3^n) with trace 0 and subtrace 0.at n=18A074000
- Number of elements of GF(3^n) with trace 1 and subtrace 0.at n=18A074003
- a(n) = (3^n + 2*3^(n/2)*cos(n*Pi/6))/3.at n=18A092236
- a(1) = a(2) = 1, a(3) = 9; for n > 3, a(n) = 3*a(n-1) - 3*a(n-2) + 9*a(n-3).at n=17A101990
- Sum 3^max(k,n-k),k=0..n.at n=16A107660
- Consider the aliquot parts, in ascending order, of a composite number. Take their sum and repeat the process deleting the minimum number and adding the previous sum. The sequence lists the numbers that after some iterations reach a sum equal to themselves.at n=15A246544
- a(n) is the number of words of length n on the alphabet {0,1,2} with the number of 0's plus the number of 1's congruent to the number of 2's modulo 3.at n=18A334656