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A092609
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Product of first n primes that end in 1.
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4
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11, 341, 13981, 852841, 60551711, 6115722811, 801159688241, 120975112924391, 21896495439314771, 4182230628909121261, 882450662699824586071, 212670609710657725243111, 53380323037375089036020861
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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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a(1)= 11 = 11
a(2)= 11*31 = 341
a(3)= 11*31*41= 13981
a(4)= 11*31*41*61= 852841
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MAPLE
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Res:= NULL: p:= 1: count:= 0:
for n from 11 by 10 while count < 30 do
if isprime(n) then count:= count+1; p:= p*n; Res:= Res, p fi
od:
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MATHEMATICA
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Rest[FoldList[Times, 1, Select[Prime[Range[70]], Mod[#, 10]==1&]]] (* Harvey P. Dale, Jun 05 2013 *)
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PROG
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(PARI) a(n) = {my(k=1, x=1); for (j=1, n, while(!isprime(10*k+1), k++); x *= (10*k+1); k++; ); x; } \\ Michel Marcus, Nov 09 2020
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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STATUS
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approved
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