A088640 - OEIS

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A088640

Smallest number suffixed to concatenation of n times n gives a prime.

2, 1, 3, 1, 9, 7, 29, 1, 3, 7, 39, 1, 23, 1, 97, 1, 91, 37, 59, 9, 93, 19, 97, 61, 293, 61, 3, 1, 57, 7, 43, 61, 7, 53, 31, 127, 353, 67, 841, 187, 9, 3, 179, 429, 127, 97, 3, 319, 11, 51, 39, 191, 33, 3, 41, 7, 39, 47, 73, 81, 401, 57, 441, 571, 957, 997, 1, 19, 291, 173, 9, 417 (list; graph; refs; listen; history; text; internal format)

	OFFSET	`0,1`
	LINKS	`Table of n, a(n) for n=0..71.`
	EXAMPLE	`a(6) = 29 and 66666629 is prime.`
	MAPLE	`a:= proc(n) local d, h, s;` `s:= parse(cat(0, n$n));` `for d from 0 do` `for h to 10^d-1 do` `if isprime(s+h) then return h fi` `od:` `s:= s*10;` `od` `end:` `seq(a(n), n=0..75); # Alois P. Heinz, Feb 11 2021`
	CROSSREFS	`Cf. A088639.` `Sequence in context: A198315 A126761 A090559 * A186725 A301935 A237978` `Adjacent sequences: A088637 A088638 A088639 * A088641 A088642 A088643`
	KEYWORD	`base,nonn`
	AUTHOR	`Amarnath Murthy, Oct 27 2003`
	EXTENSIONS	`More terms from Ray Chandler, Nov 01 2003` `a(0)=2 prepended by Alois P. Heinz, Feb 11 2021`
	STATUS	`approved`

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Last modified February 27 17:31 EST 2021. Contains 341657 sequences. (Running on oeis4.)