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A370826
a(n) are the denominators corresponding to A370825(n).
3
2, 1, 14, 1, 62, 3, 254, 17, 1022, 31, 178, 3, 16382, 5461, 65534, 257, 262142, 657, 1048574, 1271, 4194302, 60787, 356962, 12291, 67108862, 22369621, 268435454, 617093, 1073741822, 149943, 4294967294, 16843009, 746950834, 5726623061, 967879954, 981, 274877906942
OFFSET
1,1
COMMENTS
See A370825 for more information.
FORMULA
A370825(n)/a(n) = (3/4) * (3^n - 1) / (2^n - 1).
EXAMPLE
A370825(n)/a(n) for n=1..14: 3/2, 2, 39/14, 4, 363/62, 26/3, 3279/254, 328/17, 29523/1022, 1342/31, 11553/178, 292/3, 2391483/16382, 1195742/5461.
MATHEMATICA
Array[Denominator[3/4*(3^#-1)/(2^#-1)] &, 50] (* Paolo Xausa, Mar 11 2024 *)
PROG
(PARI) a370826(n) = denominator((3/4) * (3^n - 1) / (2^n - 1));
(Python)
from math import gcd
def A370826(n): return (a:=(1<<n+1)-2)//gcd(a, 3**(n+1)-3>>1) # Chai Wah Wu, Mar 10 2024
CROSSREFS
A370825 are the corresponding numerators.
Sequence in context: A286740 A285653 A280412 * A155729 A217475 A288298
KEYWORD
nonn,frac,easy
AUTHOR
Hugo Pfoertner, Mar 08 2024
STATUS
approved