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%I #18 Sep 16 2019 04:31:30
%S 2,23,235,2357,35711,571113,7111317,11131719,113171923,1317192329,
%T 31719232931,171923293137,7192329313741,19232931374143,
%U 923293137414347,2329313741434753,32931374143475359,293137414347535961,9313741434753596167,31374143475359616771,137414347535961677173,3741434753596167717379
%N Last n digits of concatenation of first n primes.
%C a(n) = A019518(n) mod 10^n; a(n) mod 10^A055642(A000040(n)) = A000040(n); for the primes in this sequence see A091763.
%H David A. Corneth, <a href="/A091762/b091762.txt">Table of n, a(n) for n = 1..1000</a>
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/ConsecutiveNumberSequences.html">Consecutive Number Sequences</a>
%e The first 5 primes are 2, 3, 5, 7, 11. The last 5 digits concatenated are 35711 so a(5) = 35711. - _David A. Corneth_, Sep 15 2019
%t Table[FromDigits[Take[Flatten[IntegerDigits/@Prime[Range[n]]],-n]],{n,20}] (* _Harvey P. Dale_, Sep 15 2019 *)
%o (PARI) a(n) = {my(p = prime(n), v = digits(p)); while(#v < n, p = precprime(p - 1); v = concat(digits(p), v)); fromdigits(vector(n, i, v[#v - n + i]))} \\ _David A. Corneth_, Sep 15 2019
%K nonn,base,easy
%O 1,1
%A _Reinhard Zumkeller_, Feb 04 2004
%E More terms from _David A. Corneth_, Sep 15 2019
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