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A335593
Numbers k such that abs(A335592(k))/2 is prime.
4
4, 17, 27, 53, 74, 91, 97, 108, 111, 139, 152, 171, 207, 242, 245, 247, 275, 280, 286, 292, 310, 323, 352, 355, 385, 398, 424, 430, 471, 476, 484, 504, 525, 551, 555, 561, 586, 615, 626, 658, 659, 705, 709, 736, 744, 754, 772, 823, 837, 841, 849, 858, 866, 869, 870, 877, 882, 896, 937, 960, 995
OFFSET
1,1
LINKS
EXAMPLE
a(3) = 27 is a term because A335592(27) = det(631, 563; 577, 619) = 65738 = 2*32869 and 32869 is prime.
MAPLE
count:= 0: R:= NULL:
L:= [-9, -7, -3, -1]:
for k from 1 while count < 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;
v:= L[1]*L[4]-L[2]*L[3];
if isprime(abs(v)/2) then count:= count+1; R:= R, k; fi
od:
R;
CROSSREFS
Sequence in context: A171227 A061387 A366210 * A319970 A272834 A273573
KEYWORD
nonn,base
AUTHOR
J. M. Bergot and Robert Israel, Jan 27 2021
STATUS
approved