login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A374581
a(n) is the denominator of (120*n^2 + 151*n + 47)/(512*n^4 + 1024*n^3 + 712*n^2 + 194*n + 15).
4
15, 819, 19635, 15225, 69597, 466785, 911547, 179645, 533715, 4165161, 2072385, 8947437, 12491175, 1133055, 22621131, 29539125, 4214903, 48002745, 11990775, 24669567, 90400695, 109375617, 43730505, 6244749, 184439871, 24049985, 252455907, 292777485, 22516425, 387706641
OFFSET
0,1
COMMENTS
See Bailey and Crandall (2001), section 5 (pp. 183-184) for a derivation of this rational polynomial.
Numerators are given by A374580.
LINKS
David H. Bailey and Richard E. Crandall, On the Random Character of Fundamental Constant Expansions, Experimental Mathematics, Vol. 10 (2001), Issue 2, pp. 175-190 (preprint draft).
FORMULA
Sum_{n >= 0} (1/16^n)*A374580(n)/a(n) = A000796. See Bailey and Crandall (2001), eq. 5-2, p. 184.
MATHEMATICA
A374581[n_] := Denominator[(120*n^2 + 151*n + 47)/(512*n^4 + 1024*n^3 + 712*n^2 + 194*n + 15)];
Array[A374581, 30, 0]
PROG
(Python)
from math import gcd
def A374581(n): return (lambda p, q: q//gcd(p, q))(n*(120*n + 151) + 47, n*(n*(n*(512*n + 1024) + 712) + 194) + 15) # Chai Wah Wu, Jul 14 2024
CROSSREFS
Cf. A000796, A001025, A374335, A374580 (numerators), A374608.
Sequence in context: A279493 A183821 A301312 * A230181 A187803 A261828
KEYWORD
nonn,frac
AUTHOR
Paolo Xausa, Jul 12 2024
STATUS
approved