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A089933 Concatenate the first n odd primes. 8
3, 35, 357, 35711, 3571113, 357111317, 35711131719, 3571113171923, 357111317192329, 35711131719232931, 3571113171923293137, 357111317192329313741, 35711131719232931374143, 3571113171923293137414347, 357111317192329313741434753, 35711131719232931374143475359 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Except for a(1) = 3, these numbers are not prime for n < 10000. See A089948.
LINKS
MAPLE
a[1]:= 3;
for n from 2 to 100 do
p:= ithprime(n+1);
a[n]:= 10^(1+ilog10(p))*a[n-1]+p
od:
seq(a[i], i=1..100); # Robert Israel, Aug 25 2016
MATHEMATICA
Table[FromDigits[Flatten[IntegerDigits[Prime[Range[n] + 1]]]], {n, 20}] (* Vincenzo Librandi, Nov 30 2015 *)
PROG
(PARI) concatprime(n) = { y=""; forprime(x=3, n, y=concat(Str(y), Str(x)); z=eval(y); print1(z", ") ) }
(Magma) [Seqint(Reverse(&cat[Reverse(Intseq(NthPrime(k+1))): k in [1..n]])): n in [1..17]]; // Vincenzo Librandi, Nov 30 2015
CROSSREFS
Sequence in context: A112488 A221922 A260586 * A086043 A221774 A221687
KEYWORD
nonn,base
AUTHOR
Cino Hilliard, Jan 11 2004
EXTENSIONS
Offset changed by Robert Israel, Aug 25 2016
STATUS
approved

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Last modified April 27 04:50 EDT 2024. Contains 372009 sequences. (Running on oeis4.)