

A115426


Numbers n such that the concatenation of n with n+2 gives a square.


24



7874, 8119, 69476962, 98010199, 108746354942, 449212110367, 544978035127, 870501316279, 998001001999, 1428394731903223, 1499870932756487, 1806498025502498, 1830668275445687, 1911470478658759, 2255786189655202
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,1


COMMENTS

Numbers n such that n concatenated with n+1 gives the product of two numbers which differ by 2.
Numbers n such that n concatenated with n2 gives the product of two numbers which differ by 4.
Numbers n such that n concatenated with n7 gives the product of two numbers which differ by 6.


LINKS

Table of n, a(n) for n=1..15.


EXAMPLE

8119//8121 = 9011^2, where // denotes concatenation.
98010199//98010200 = 99000100 * 99000102.
98010199//98010197 = 99000099 * 99000103.


CROSSREFS

Cf. A030465, A102567, A115427, A115428, A115429, A115430, A115431, A115432, A115433, A115434, A115435, A115436, A115437.
Cf. A116106, A116110, A116112, A116125, A116242.
Cf. A116136, A116143, A116107, A116275, A116163, A116099, A116177, A116295.
Sequence in context: A286208 A268583 A045292 * A206069 A237969 A256163
Adjacent sequences: A115423 A115424 A115425 * A115427 A115428 A115429


KEYWORD

base,nonn


AUTHOR

Giovanni Resta, Jan 24 2006


EXTENSIONS

Edited by N. J. A. Sloane, Apr 13 2007


STATUS

approved



