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 A116185 Numbers k such that k concatenated with k+4 gives the product of two numbers which differ by 3. 6
 150, 186, 324, 376, 666, 2046, 3000, 82650, 100384, 466716, 1322316, 4049584, 67820074, 110003884, 135734074, 156502836, 196043286, 213017754, 238849000, 261405396, 289940826, 310507774, 365294050, 398891964, 446667216 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Also numbers k such that k concatenated with k+6 gives the product of two numbers which differ by 1. LINKS MAPLE cc:=proc(x, y) local s: s:=proc(m) nops(convert(m, base, 10)) end: x*10^s(y)+y: end: a:=proc(n) if type(sqrt(9+4*cc(n, n+4)), integer) then n else fi end: seq(a(n), n=1..500000); # very slow; cc yields the concatenation of x and y; - Emeric Deutsch, May 05 2007 CROSSREFS Cf. A116112, A115428, A115429, A116316, A116199, A116172, A116329. Sequence in context: A104262 A048706 A054729 * A008889 A184075 A207044 Adjacent sequences:  A116182 A116183 A116184 * A116186 A116187 A116188 KEYWORD nonn,base,changed AUTHOR Giovanni Resta, Feb 06 2006 EXTENSIONS Edited by N. J. A. Sloane, Apr 14 2007 STATUS approved

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Last modified July 28 12:59 EDT 2021. Contains 346331 sequences. (Running on oeis4.)