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A090510 a(n) is the least prime beginning with prime(n) such that the concatenation a(1)a(2)...a(n) is a prime. 2
2, 3, 509, 79, 1163, 13033, 1721, 19, 233, 29569, 3119, 37057, 410171, 43003, 47111, 5323, 59219, 61291, 670223, 710911, 73331, 795793, 83399, 894709, 975581, 101383, 1033079, 1071937, 109073, 1130257, 1276397, 1313911, 1378673, 1395469, 1491233 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
MAPLE
dcat:= proc(a, b) 10^(1+ilog10(b))*a+b end proc:
S:= 2: R:= 2:
for n from 2 to 35 do
found:= false;
for d from 0 while not found do
cand:= 10^d*ithprime(n)-1;
do
cand:= nextprime(cand);
if cand >= 10^d*(ithprime(n)+1) then break fi;
Sc:= dcat(S, cand);
if isprime(Sc) then found:= true; break fi
od od;
R:= R, cand;
S:= Sc;
od:
R; # Robert Israel, Aug 06 2020
CROSSREFS
Cf. A090511.
Sequence in context: A128874 A196070 A173342 * A348360 A004887 A240709
KEYWORD
base,nonn
AUTHOR
Amarnath Murthy, Dec 06 2003
EXTENSIONS
More terms from Max Alekseyev, Feb 08 2010
STATUS
approved

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Last modified June 14 23:20 EDT 2024. Contains 373401 sequences. (Running on oeis4.)