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A128664 Rounded first term of asymptotic approximation to A003823. 0
1, 1, 0, -1, 0, 1, 1, -1, -2, 0, 2, 2, -1, -3, -1, 3, 3, -2, -5, -1, 5, 5, -3, -8, -2, 8, 8, -5, -12, -2, 13, 11, -7, -18, -4, 18, 17, -10, -26, -5, 27, 24, -15, -37, -7, 38, 33, -21, -52, -10, 52, 46, -29, -72, -14, 72, 64, -40, -98, -20, 98, 87, -54, -133, -27, 132, 116, -72, -178, -36, 176, 155, -96, -236, -47, 233, 205, -126 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,9

REFERENCES

B. Cais and B. Conrad, Modular curves and Ramanujan's continued fraction, J. Reine Angew. Math. 597 (2006), 27-104. See page 69 (7.27). MR2264315

LINKS

Table of n, a(n) for n=0..77.

PROG

(PARI) {a(n)= if(n<1, n==0, round( 4/5*Pi/ sqrt(5*n-1)* cos(2/25*Pi* (5*n-2))* besseli(1, 4/25*Pi* sqrt(5*n-1))) )}

CROSSREFS

Sequence in context: A156643 A308626 A268755 * A003823 A059451 A083817

Adjacent sequences:  A128661 A128662 A128663 * A128665 A128666 A128667

KEYWORD

sign

AUTHOR

Michael Somos, Mar 19 2007

STATUS

approved

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Last modified December 3 16:20 EST 2020. Contains 338906 sequences. (Running on oeis4.)