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A335592 a(n) is the determinant of the 2 X 2 matrix whose entries (listed by rows) are the n-th prime ending in 1, 3, 7, 9 respectively. 4
188, 678, 1568, 2798, 2768, 3928, 9328, 9418, 16918, 12418, 19428, 19578, 16898, 34698, 28028, 30988, 35878, 58528, 53908, 52318, 54938, 37308, 53098, 49888, 49758, 68688, 65738, 74328, 96558, 100098, 95548, 121898, 119108, 117438, 104078, 140698, 156588, 143168, 222888, 226608, 196448, 160448 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

All terms == 8 (mod 10).

Are there negative terms?  The first 10^7 are positive.

LINKS

Robert Israel, Table of n, a(n) for n = 1..10000

EXAMPLE

The first primes ending in 1,3,7,9 are 11,3,7,19, so a(1) = 11*19 - 3*7 = 188.

The second primes ending in 1,3,7,9 are 31,13,17,29, so a(2) = 31*29 - 13*17 = 678.

The third primes ending in 1,3,7,9 are 41,23,37,59, so a(3) = 41*59 - 23*37 = 1568.

MAPLE

R:= NULL:

L:= [-9, -7, -3, -1]:

for k from 1 to 100 do

  for i from 1 to 4 do

   for x from L[i]+10 by 10 do until isprime(x);

   L[i]:= x;

  od;

  R:= R, L[1]*L[4]-L[2]*L[3];

od:

R;

CROSSREFS

Cf. A335581, A335593, A336738.

Sequence in context: A304279 A099945 A211814 * A233786 A233961 A073586

Adjacent sequences:  A335589 A335590 A335591 * A335593 A335594 A335595

KEYWORD

nonn,base,look

AUTHOR

J. M. Bergot and Robert Israel, Jan 27 2021

STATUS

approved

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Last modified September 18 05:34 EDT 2021. Contains 347509 sequences. (Running on oeis4.)