|
Search: id:A116172
|
|
|
| A116172 |
|
Numbers n such that n concatenated with n+2 gives the product of two numbers which differ by 5. |
|
+0
12
|
|
| 2, 74, 59264, 510782, 906902, 81790664, 92776472, 10876856041862, 11796926254874, 18332259798794, 18388650720624, 32624670587648, 32699883214248, 43103618706398, 44916698243804, 66132258426302
(list; graph; listen)
|
|
|
OFFSET
|
1,1
|
|
|
COMMENT
|
Also numbers n such that n concatenated with n+6 gives the product of two numbers which differ by 3.
Also numbers n such that n concatenated with n+8 gives the product of two numbers which differ by 1.
If n+2 and n-4 have the same number of digits, then n is also in A116132 because n//n+2=10^d*n+n+2=k(k+5) then implies n//n-4=10^d*n+n-4=k(k+5)-6=(k-1)(k+6). [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Aug 10 2008]
|
|
EXAMPLE
|
92776472//92776474 = 96320542 * 96320547, where // denotes concatenation.
92776472//92776480 = 96320544 * 96320545.
92776472//92776478 = 96320543 * 96320546.
|
|
CROSSREFS
|
Cf. A116158, A116171, A116173, A116179, A116303.
Cf. A116185, A115430, A116205, A116343, A116200, A116330.
Adjacent sequences: A116169 A116170 A116171 this_sequence A116173 A116174 A116175
Sequence in context: A041647 A083018 A062552 this_sequence A000329 A091978 A087287
|
|
KEYWORD
|
nonn,base
|
|
AUTHOR
|
Giovanni Resta (g.resta(AT)iit.cnr.it), Feb 06 2006
|
|
EXTENSIONS
|
Edited by njas, Apr 15 2007
|
|
|
Search completed in 0.002 seconds
|
