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A116320 n times n+8 gives the concatenation of two numbers m and m+4. 6
4, 86, 32762, 67231, 76322, 693956, 900097, 7295105, 9068525, 3664355432, 6335644561, 8015841979, 8419801579, 9900000997, 3252382148828, 6747617851165, 7253863787097, 9474890578438, 9981136514370 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Includes 10^(4*k+2)-10^(3*k+2)+10^(k+1)-3 for k >= 1. - Robert Israel, Jun 20 2018

LINKS

Robert Israel, Table of n, a(n) for n = 1..2282

MAPLE

Res:= NULL: count:= 0:

for d from 1 while count < 100 do

  R:= sort(select(t -> t^2 + 8*t - 4 > 10^(2*d-1) and t^2+8*t-4 < 10^(2*d), map(t -> rhs(op(t)), [msolve(n^2+8*n-4, 10^d+1)])));

  count := count+nops(R);

  Res:= Res, op(R);

od:

Res; # Robert Israel, Jun 20 2018

CROSSREFS

Cf. A116189, A116312, A116319, A116321, A116327.

Sequence in context: A293318 A204460 A162086 * A220277 A122209 A059577

Adjacent sequences:  A116317 A116318 A116319 * A116321 A116322 A116323

KEYWORD

nonn,base,look

AUTHOR

Giovanni Resta, Feb 06 2006

STATUS

approved

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Last modified September 28 06:57 EDT 2021. Contains 347703 sequences. (Running on oeis4.)