The On-Line Encyclopedia of Integer Sequences (OEIS)

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A255491

Numbers k such that 90*k+1 is composite.
(history; published version)

#9 by Charles R Greathouse IV at Thu Sep 08 08:46:11 EDT 2022

PROG

(MAGMAMagma) [n: n in [1..120]| not IsPrime(90*n+1)]; // Vincenzo Librandi, Jun 09 2017

Discussion

Thu Sep 08

08:46

OEIS Server: https://oeis.org/edit/global/2944

#8 by Bruno Berselli at Fri Jun 09 03:11:53 EDT 2017

STATUS

editing

approved

#7 by Bruno Berselli at Fri Jun 09 03:11:49 EDT 2017

NAME

Numbers n k such that 90*nk+1 is composite.

STATUS

approved

editing

#6 by Bruno Berselli at Fri Jun 09 03:10:30 EDT 2017

STATUS

proposed

approved

#5 by Vincenzo Librandi at Fri Jun 09 01:51:25 EDT 2017

STATUS

editing

proposed

#4 by Vincenzo Librandi at Fri Jun 09 01:51:10 EDT 2017

LINKS

Vincenzo Librandi, <a href="/A255491/b255491.txt">Table of n, a(n) for n = 1..7000</a>

MATHEMATICA

Select[Range[200], !PrimeQ[90 # + 1] &] (* Vincenzo Librandi, Jun 09 2017 *)

PROG

(MAGMA) [n: n in [1..120]| not IsPrime(90*n+1)]; // Vincenzo Librandi, Jun 09 2017

STATUS

approved

editing

#3 by N. J. A. Sloane at Tue Mar 03 08:07:56 EST 2015

STATUS

editing

approved

#2 by N. J. A. Sloane at Tue Mar 03 08:07:51 EST 2015

NAME

allocated for N. J. A. Sloane

Numbers n such that 90*n+1 is composite.

DATA

1, 4, 5, 8, 10, 12, 14, 15, 16, 19, 21, 22, 23, 27, 29, 30, 32, 35, 36, 38, 40, 42, 43, 44, 46, 48, 49, 50, 52, 53, 56, 57, 58, 59, 60, 61, 63, 64, 66, 67, 71, 75, 77, 78, 79, 80, 81, 82, 83, 85, 87, 88, 92, 93, 95, 99, 103, 104, 105, 106

OFFSET

1,2

REFERENCES

J. W. Helkenberg, Email message, Mar 02 2015.

CROSSREFS

Complement of A181732.

KEYWORD

allocated

nonn

AUTHOR

N. J. A. Sloane, Mar 03 2015

STATUS

approved

editing

#1 by N. J. A. Sloane at Mon Feb 23 22:30:53 EST 2015

NAME

allocated for N. J. A. Sloane

KEYWORD

allocated

STATUS

approved