A261419 Numerators of coefficients in Taylor series expansion of sqrt( 1 + Sum_{k>=1} k^2*x^k ).

1, 1, 15, 57, 571, 919, 1531, 2313, 193107, 923755, 3870833, -2470257, -146827409, -230596717, 2290003475, 13080152617, 253889113987, -1578843080909, -15542657972939, -10764297242445, 612468847320021, 2467732201838601, 847831210033293, -57573918082836705

Offset

0,3

Links

Table of n, a(n) for n=0..23.

Example

The coefficients are 1, 1/2, 15/8, 57/16, 571/128, 919/256, 1531/1024, 2313/2048, 193107/32768, 923755/65536, 3870833/262144, -2470257/524288, -146827409/4194304, -230596717/8388608, 2290003475/33554432, 13080152617/67108864, 253889113987/2147483648, ... [corrected by Ilya Gutkovskiy, Aug 03 2023]

Crossrefs

The denominators appear to be A046161.

Sequence in context: A184223 A084815 A240152 * A183942 A012691 A020187

Adjacent sequences: A261416 A261417 A261418 * A261420 A261421 A261422

Keyword

sign,frac

Author

N. J. A. Sloane, Aug 27 2015

Status

approved