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A116345 Numbers k such that k*(k+6) gives the concatenation of two numbers m and m+8. 6
41, 54, 40354308, 59645687, 39704957106129738595969799927611, 44505281604832422780051712184760, 45053875613995255103944518907120, 54946124386004744896055481092875, 55494718395167577219948287815235, 60295042893870261404030200072384, 68683652917306421895276391964227 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
EXAMPLE
59645687 * 59645693 = 35576083//35576091, where // denotes concatenation.
MAPLE
f:= proc(d) local R;
R:= map(rhs@op, {msolve(x^2=17, 10^d+1)});
R:= map(t -> (t-3) mod (10^d+1), R);
op(select(proc(t) local m; m:= (t*(t+6)-8)/(10^d+1)+8; m >= 10^(d-1) and m < 10^d end proc, R));
end proc;
sort(convert({seq(f(i), i=1..50)}, list)); # Robert Israel, Jan 17 2017
CROSSREFS
Sequence in context: A367421 A282353 A118636 * A127333 A262722 A172406
KEYWORD
nonn,base
AUTHOR
Giovanni Resta, Feb 06 2006
EXTENSIONS
More terms from Robert Israel, Jan 17 2017
STATUS
approved

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Last modified May 24 21:03 EDT 2024. Contains 372781 sequences. (Running on oeis4.)