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Revision History for A358312

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Consider the graph of symmetric primes where p and q are connected if |p-q| = gcd(p-1,q-1). This sequence is an irregular table where the n-th row lists the first symmetric prime in a connected component with n vertices, with one representative for each nonisomorphic graph. Within a row, graphs are ordered by increasing size of its initial prime.
(history; published version)
#5 by Michael De Vlieger at Thu Nov 17 07:20:26 EST 2022
STATUS

proposed

approved

#4 by Charles R Greathouse IV at Tue Nov 15 11:13:39 EST 2022
STATUS

editing

proposed

#3 by Charles R Greathouse IV at Tue Nov 08 12:09:34 EST 2022
COMMENTS

Row lengths are A001349(n); if the sequence is finite the last row may be shorter.

Kalmynin gives T(2, 1) = 3343 and proves that, under a conjecture which is intermediate between Dickson's conjecture and the Bateman-Horn-Stemmler conjecture, that this sequence is infinite.

#2 by Charles R Greathouse IV at Tue Nov 08 11:51:17 EST 2022
NAME

allocated Consider the graph of symmetric primes where p and q are connected if |p-q| = gcd(p-1,q-1). This sequence is an irregular table where the n-th row lists the first symmetric prime in a connected component with n vertices, with one representative for Charles R Greathouse IVeach nonisomorphic graph. Within a row, graphs are ordered by increasing size of its initial prime.

DATA

3343, 42293, 461393, 70793, 72053, 268267, 8917219

OFFSET

2,1

COMMENTS

Kalmynin gives T(2, 1) = 3343.

LINKS

A. B. Kalmynin, <a href="http://math.colgate.edu/~integers/v2/v2.pdf">On the Symmetry Graph of Prime Numbers</a>, INTEGERS 21 (2021), #A2.

EXAMPLE

T(2, 1) = 3343 has components {3343, 4457} which form the complete graph K_2.

T(3, 1) = 42293 has components {42293, 42487, 63439} which form the path graph P_3.

T(3, 2) = 461393 has components {461393, 519067, 692089} which form the complete graph K_3.

T(4, 1) = 70793 has components {70793, 106187, 106189, 123887} which form the claw graph.

T(4, 2) = 72053 has components {72053, 108079, 216157, 288209} which form the path graph P_4.

T(4, 3) = 268267 has components {268267, 357689, 536531, 536533} which form the paw graph.

T(4, 4) = 8917219 has components {8917219, 9908021, 14862031, 17834437} which form the square graph.

CROSSREFS

Cf. A090190.

KEYWORD

allocated

nonn,tabf,hard,more

AUTHOR
STATUS

approved

editing

Discussion
Tue Nov 08
11:51
Charles R Greathouse IV: The title is unwieldy; feel free to improve!
#1 by Charles R Greathouse IV at Tue Nov 08 11:51:17 EST 2022
NAME

allocated for Charles R Greathouse IV

KEYWORD

allocated

STATUS

approved