login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A135212 a(n) = A078456(n)/A120271(n). 3
1, 1, 2, 4, 8, 576, 1152, 2304, 4608, 18432, 552960, 59719680, 2388787200, 100329062400, 200658124800, 802632499200, 1605264998400, 288947699712000, 6356849393664000, 444979457556480000, 10679506981355520000 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

LINKS

G. C. Greubel, Table of n, a(n) for n = 1..250

FORMULA

a(n) = A078456(n)/A120271(n).

MATHEMATICA

Table[ Det[ DiagonalMatrix[ Table[ Prime[i+1]-1, {i, 1, n-1} ] ] + 1 ], {n, 1, 50} ] / Numerator[ Table[ Sum[ 1/(Prime[i]-1), {i, 1, n} ], {n, 1, 50}] ]

PROG

(PARI) a(n) = matdet(matrix(n-1, n-1, j, k, if (j==k, prime(j+1), 1)))/numerator(sum(k=1, n, 1/(prime(k)-1))); \\ Michel Marcus, Oct 02 2016

CROSSREFS

Cf. A078456, A120271.

Sequence in context: A302864 A061089 A067499 * A012456 A071686 A296742

Adjacent sequences:  A135209 A135210 A135211 * A135213 A135214 A135215

KEYWORD

nonn

AUTHOR

Alexander Adamchuk, Nov 23 2007

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified July 10 12:34 EDT 2020. Contains 335576 sequences. (Running on oeis4.)