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A116193
Numbers k such that k concatenated with k+5 gives the product of two numbers which differ by 5.
11
11, 45, 18281, 32769, 56891, 180689, 330539, 959481, 1850201, 3247409, 4940219, 2425563239, 2575561739, 6003563495, 7245212645, 7770160145, 4983798265289, 5049762270381, 5534298528989, 5603798594169, 21894082450101
OFFSET
1,1
COMMENTS
Also numbers k such that k concatenated with k+9 gives the product of two numbers which differ by 3. For proof that this is the same sequence compare A116133.
Also numbers k such that k concatenated with k-9 gives the product of two numbers which differ by 9.
EXAMPLE
7770160145//7770160136 = 8814851183 * 8814851192, where // denotes concatenation.
KEYWORD
nonn,base
AUTHOR
Giovanni Resta, Feb 06 2006
EXTENSIONS
Edited by N. J. A. Sloane, Apr 12 2007
STATUS
approved