OFFSET
1,2
COMMENTS
This sequence is the main diagonal of A326376.
FORMULA
EXAMPLE
The first terms, alongside the corresponding polynomials, are:
n a(n) f(n) f(n) o f(n)
-- ---- ----- -----------
1 1 0 0
2 2 1 1
3 3 x x
4 4 2 2
5 11 x^2 x^4
6 12 x+1 x+2
7 29 x^3 x^9
8 8 3 3
9 81 2*x 4*x
10 1100 x^2+1 x^4+2*x^2+2
11 59 x^4 x^16
12 48 x+2 x+4
PROG
(PARI) g(p) = my (c=Vecrev(Vec(p))); prod (i=1, #c, if (c[i], prime(i)^c[i], 1))
f(n, v='x) = my (f=factor(n)); sum (i=1, #f~, f[i, 2] * v^(primepi(f[i, 1]) - 1))
a(n) = g(f(n, f(n)))
CROSSREFS
KEYWORD
nonn
AUTHOR
Rémy Sigrist, Jul 02 2019
STATUS
approved