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A092609 Product of first n primes that end in 1. 4
11, 341, 13981, 852841, 60551711, 6115722811, 801159688241, 120975112924391, 21896495439314771, 4182230628909121261, 882450662699824586071, 212670609710657725243111, 53380323037375089036020861 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Robert Israel, Table of n, a(n) for n = 1..286

EXAMPLE

a(1)= 11 = 11

a(2)= 11*31 = 341

a(3)= 11*31*41= 13981

a(4)= 11*31*41*61= 852841

MAPLE

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:

Res; # Robert Israel, Sep 16 2018

MATHEMATICA

Rest[FoldList[Times, 1, Select[Prime[Range[70]], Mod[#, 10]==1&]]] (* Harvey P. Dale, Jun 05 2013 *)

PROG

(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

CROSSREFS

Cf. A030430.

Sequence in context: A219072 A280669 A195505 * A091537 A327943 A277348

Adjacent sequences:  A092606 A092607 A092608 * A092610 A092611 A092612

KEYWORD

nonn,easy

AUTHOR

Jorge Coveiro, Apr 11 2004

STATUS

approved

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Last modified January 24 13:05 EST 2022. Contains 350538 sequences. (Running on oeis4.)