id:A134428 - OEIS Search Results

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Primes formed by concatenating n with n+1, where n+1 is a prime.

+0
1

23, 67, 1213, 3637, 4243, 7879, 9697, 102103, 108109, 126127, 138139, 150151, 156157, 180181, 192193, 270271, 276277, 312313, 330331, 378379, 420421, 432433, 438439, 456457, 522523, 540541, 546547, 576577, 600601, 606607, 612613, 618619 (list; graph; listen)

	OFFSET	`0,1`
	COMMENT	`Subset of A030458 and A052087`
	MAPLE	`P:=proc(n) local a, b, c, i; for i from 1 by 1 to n do a:=ithprime(i)-1; b:=a; c:=0; while b>0 do c:=c+1; b:=trunc(b/10); od; b:=a*10^c+ithprime(i); if isprime(b) then print(b); fi; od; end: P(1000);`
	CROSSREFS	`Cf. A030458, A052087.` `Sequence in context: A136064 A142302 A078622 this_sequence A042036 A042034 A042038` `Adjacent sequences: A134425 A134426 A134427 this_sequence A134429 A134430 A134431`
	KEYWORD	`easy,nonn,base`
	AUTHOR	`Paolo P. Lava & Giorgio Balzarotti (ppl(AT)spl.at), Jan 18 2008`

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Last modified December 4 21:35 EST 2008. Contains 151309 sequences.

AT&T Labs Research