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A116437 Numbers n which when sandwiched between two 2's give a multiple of n. 2
1, 2, 11, 13, 14, 22, 26, 77, 91, 137, 146, 274, 9091, 19802, 909091, 5882353, 10989011, 12987013, 13986014, 15037594, 21978022, 25974026, 52631579, 76923077, 90909091, 198019802, 1652892562, 4347826087, 8695652174 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..29.

EXAMPLE

77 belongs since 2772 is a multiple of 77 (77*36).

MATHEMATICA

f[k_, d_] := Flatten@Table[Select[Divisors[k*(10^(i + 1) + 1)], IntegerLength[ # ] == i &], {i, d}]; f[2, 10] (* Ray Chandler, May 11 2007 *)

CROSSREFS

Cf. A116436-A116444.

Sequence in context: A127303 A286153 A068972 * A048867 A113626 A154539

Adjacent sequences:  A116434 A116435 A116436 * A116438 A116439 A116440

KEYWORD

base,nonn

AUTHOR

Giovanni Resta, Feb 15 2006

STATUS

approved

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Last modified August 8 14:04 EDT 2020. Contains 336298 sequences. (Running on oeis4.)