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A234315 Let x(0)x(1)x(2)... x(q) denote the decimal expansion of n. Sequence lists the numbers n such that the suffix of decimal expansion x(2)... x(q) is the p-th divisor of n where p is the prefix of decimal expansion x(0)x(1). 1
1280, 1872, 10020, 10050, 12040, 12500, 14200, 17200, 19250, 24150, 42336, 46920, 100020, 100032, 100125, 110176, 120160, 120200, 141250, 170040, 180300, 190152, 200800, 220200, 220880, 222500, 230100, 240640, 251250, 260100, 262000, 270180, 270750, 291450 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..34.

EXAMPLE

1872 is in the sequence because the divisors of 1872 are {1, 2, 3, 4, 6, 8, 9, 12, 13, 16, 18, 24, 26, 36, 39, 48, 52, 72, 78, 104, 117, 144, 156, 208, 234, 312, 468, 624, 936, 1872} and 72 is the 18th divisor of 1872.

MAPLE

with(numtheory):for n from 1000 to 500000 do:x:=convert(n, base, 10):n1:=nops(x):y:=divisors(n):n2:=nops(y):a:=x[n1]*10+x[n1-1]: s:=sum('x[i]*10^(i-1) ', 'i'=1..n1-2):if n2>a and y[a]=s then printf(`%d, `, n):else fi:od:

CROSSREFS

Cf. A234314.

Sequence in context: A251894 A251791 A251784 * A251783 A224645 A237953

Adjacent sequences:  A234312 A234313 A234314 * A234316 A234317 A234318

KEYWORD

nonn,base

AUTHOR

Michel Lagneau, Dec 23 2013

STATUS

approved

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Last modified December 8 08:06 EST 2021. Contains 349594 sequences. (Running on oeis4.)