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).

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

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