The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A216533 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A216533

Numbers n such that (10^n + 1)/11 is prime, but cannot be written in the form a^2 + 7*b^2.
(history; published version)

#16 by N. J. A. Sloane at Thu May 02 13:03:36 EDT 2013

NAME

Numbers n such that (10^n + 1)/11 is prime, but cannot be written in the form a^2 + 7*b^2.

DATA

5, 53, 293, 641, 3011

OFFSET

1,1

COMMENTS

These exponents are congruent to {2, 4, 5} mod 6.

LINKS

Samuel S. Wagstaff, Jr. <a href="http://homes.cerias.purdue.edu/~ssw/cun/index.html">The Cunningham Project</a>

CROSSREFS

Cf. A001562.

KEYWORD

recycled

nonn

AUTHOR

V. Raman, Sep 08 2012

STATUS

proposed

approved

#15 by V. Raman at Thu May 02 10:21:55 EDT 2013

STATUS

editing

proposed

#14 by V. Raman at Thu May 02 09:56:08 EDT 2013

NAME

Numbers n such that (10^n + 1)/11 is prime, but cannot be written in the form a^2 + 7*b^2.

DATA

5, 53, 293, 641, 3011

OFFSET

1,1

COMMENTS

These exponents are congruent to {2, 4, 5} mod 6.

LINKS

Samuel S. Wagstaff, Jr. <a href="http://homes.cerias.purdue.edu/~ssw/cun/index.html">The Cunningham Project</a>

CROSSREFS

Cf. A001562.

KEYWORD

nonn

recycled

AUTHOR

V. Raman, Sep 08 2012

STATUS

approved

editing

#13 by T. D. Noe at Mon Sep 17 11:29:45 EDT 2012

STATUS

editing

approved

#12 by T. D. Noe at Mon Sep 17 11:29:41 EDT 2012

NAME

Numbers n such that (10^n + 1)/11 is prime, but n cannot be written in the form a^2 + 7*b^2.

STATUS

approved

editing

#11 by Bruno Berselli at Fri Sep 14 02:30:30 EDT 2012

STATUS

proposed

approved

#10 by V. Raman at Thu Sep 13 16:50:41 EDT 2012

STATUS

editing

proposed

#9 by V. Raman at Thu Sep 13 16:50:27 EDT 2012

NAME

Numbers n such that (10^n + 1 )/11 is prime, but n cannot be written in the form a^2 + 7*b^2.

STATUS

approved

editing

#8 by T. D. Noe at Thu Sep 13 15:13:15 EDT 2012

STATUS

editing

approved

#7 by T. D. Noe at Thu Sep 13 15:13:11 EDT 2012

NAME

Numbers n such that (10^n+1) is prime, but n cannot be written in the form a^2 + 7*b^2.

STATUS

proposed

editing