A370828 a(n) are the denominators corresponding to A370827(n).

2, 32, 392, 4352, 46112, 3584, 4860032, 49160192, 494961152, 451796992, 49818601472, 288555008, 4993469652992, 49960817917952, 499764907507712, 294034673238016, 49991536670277632, 3759016691892224, 4999695320129994752, 4545288356434542592, 11627651895922786304

Offset

1,1

Comments

See A370827 and A370823 for more information.

Links

Table of n, a(n) for n=1..21.

Formula

A370827(n)/a(n) = (2/3) * (3/5)^n * ((5/2)^n - 1) / (1 - (3/5)^n).

Example

A370827(n)/a(n) for n = 1..8: 3/2, 63/32, 1053/392, 16443/4352, 250533/46112, 28431/3584, 56859813/4860032, 853737003/49160192.

Prog

(PARI) a370828(n) = denominator((2/3) * (3/5)^n * ((5/2)^n - 1) / (1 - (3/5)^n))
(Python)
from math import gcd
def A370828(n): return (a:=5**n-3**n<<n-1)//gcd(a, 3**(n-1)*(5**n-(1<<n))) # Chai Wah Wu, Mar 12 2024

Crossrefs

A370827 are the corresponding numerators.

Sequence in context: A199019 A127697 A191467 * A282881 A230567 A340345

Adjacent sequences: A370825 A370826 A370827 * A370830 A370831 A370832

Keyword

nonn,frac,easy

Author

Hugo Pfoertner, Mar 09 2024

Status

approved