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A274527
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Prime numbers p such that p+2, p^2+p-1, p^2+p+1, p^2+3*p+1, p^2+3*p+3 are all prime numbers.
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1
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5, 2729, 26449079, 27188279, 44521679, 46090379, 52736249, 62320439, 70777979, 92520539, 109505969, 192153149, 274448789, 288269519, 343801919, 359240069, 515694899, 521594639, 527159429, 660223409, 809600819, 857353139, 921868289, 945420629, 1000777049
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listen;
history;
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OFFSET
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1,1
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LINKS
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EXAMPLE
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2 first prime, 2+2=4 composite.
3 prime, 3+2=5 prime, 3^2+3-1=11 prime, 3^2+3+1=13 prime, 3^2+3*3+1=19 prime, 3^2+3*3+3=21 composite.
5 prime, 5+2=7 prime, 5^2+5-1=29 prime, 5^2+5+1=31 prime, 5^2+3*5+1=41 prime, 5^2+3*5+3=43 prime so a(1)=5
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MATHEMATICA
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Select[Prime[Range[50890000]], AllTrue[{#+2, #^2+#-1, #^2+#+1, #^2+3#+1, #^2+3#+3}, PrimeQ]&] (* Harvey P. Dale, Aug 13 2021 *)
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PROG
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(PFGW & SCRIPT)
twin.txt file with the smallest of twin pairs.
SCRIPT
DIM m
DIM n
OPENFILEIN maf, twin.txt
OPENFILEOUT myf, a.txt
LABEL loop
GETNEXT n, maf
SET m, n*(n+1)-1
PRP m
IF ISPRP THEN GOTO a
GOTO loop
LABEL a
PRP m+2
IF ISPRP THEN GOTO b
GOTO loop
LABEL b
SET n, n+2
SET m, n*(n-1)-1
PRP m
IF ISPRP THEN GOTO c
GOTO loop
LABEL c
SET m, m+2
PRP m
SET n, n-2
IF ISPRP THEN WRITE myf, n
GOTO loop
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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