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A155074 Primes that appear as a substring in the concatenation of primes. 0

%I #4 Jan 16 2013 07:59:03

%S 23,31,71,113,131,167,271,293,317,347,359,373,379,389,491,571,631,673,

%T 677,719,761,773,811,877,911,929,937,941,971,983,997,1031,1091,1103,

%U 1171,1193,1223,1231,1283,1291,1361,1409,1433,1511,1523,1531,1571,1607

%N Primes that appear as a substring in the concatenation of primes.

%C Start with a blank concatenation string S. Does prime p(1)=2 appear in string S? No. Concatenate 2 to string S. Does prime p(2)=3 appear in string S="2"? No. Concatenate 3 to string S. Does prime p(3)=5 appear in string S="23"? No. Concatenate 5 to string S. and so on Does prime p(9)=23 appear in string S="235711131719"? Yes. 23 is in the sequence. Do not concatenate 23 to string S.

%e a(1)= 23 because 23 appears in the string 235711131719. a(3)= 71 because 71 appears in the string 235711131719293741434753596167. (Notice "23" is omitted from the string here: 235711131719--293741434753596167.)

%K easy,nonn,base

%O 1,1

%A _Gil Broussard_, Jan 19 2009

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Last modified March 29 07:27 EDT 2024. Contains 371265 sequences. (Running on oeis4.)