A016821 a(n) = (4n+1)^9.

1, 1953125, 387420489, 10604499373, 118587876497, 794280046581, 3814697265625, 14507145975869, 46411484401953, 129961739795077, 327381934393961, 756680642578125, 1628413597910449, 3299763591802133, 6351461955384057, 11694146092834141, 20711912837890625, 35452087835576229

Offset

0,2

Links

Table of n, a(n) for n=0..17.

Index entries for linear recurrences with constant coefficients, signature (10,-45,120,-210,252,-210,120,-45,10,-1).

Formula

From Amiram Eldar, Apr 21 2023: (Start)

a(n) = A016813(n)^9.

Sum_{n>=0} 1/a(n) = 277*Pi^9/16515072 + 511*zeta(9)/1024. (End)

Mathematica

Table[(4n+1)^9, {n, 0, 100}] (* Mohammad K. Azarian, Jun 20 2016 *)
LinearRecurrence[{10, -45, 120, -210, 252, -210, 120, -45, 10, -1}, {1, 1953125, 387420489, 10604499373, 118587876497, 794280046581, 3814697265625, 14507145975869, 46411484401953, 129961739795077}, 20] (* Harvey P. Dale, Sep 24 2022 *)

Crossrefs

Cf. A013667, A016813.

Sequence in context: A186578 A186579 A290500 * A016857 A016977 A017049

Adjacent sequences: A016818 A016819 A016820 * A016822 A016823 A016824

Keyword

nonn,easy

Author

N. J. A. Sloane

Status

approved