A088376 Numbers n such that n divides the concatenation of all divisors of n in ascending order other than 1 and n itself.

8, 75, 1875, 3267, 5625, 46875, 1171875, 3951075

Offset

1,1

Links

Table of n, a(n) for n=1..8.

Example

a{2}=75 because the divisors of 75 are 1, 3, 5, 15, 25 and 75, excluding 1 and 75 and concatenating in ascending order yields 351525 which is divisible by 75 (351525/75 = 4687).

Maple

divisorCat := proc(upLim, timeLimit, dvc) local s, m, n, d, t, f, startTime, startSet; startTime := time(); s := dvc[1]; m := dvc[2]; for n from s to upLim while time()-startTime<timeLimit do; d := divisors(n); d := d minus {1, n}; if d<>{} then t := ""; for f in d do; t := sprintf("%s%d", t, f); od; if parse(t) mod n = 0 then m := m union {n}; print(n, d, t, parse(t)/n); fi; fi; if n mod 10000=0 then printf("%10.4f secs ... testing %d ", time()-startTime, n) fi; od; [n-1, m]; end;

Mathematica

Select[Range[2, 1000000], !PrimeQ[#]&&Divisible[FromDigits[ Flatten[ IntegerDigits/@ Most[Rest[Divisors[#]]]]], #]&] (* Harvey P. Dale, May 03 2014 *)

Crossrefs

Sequence in context: A273998 A111685 A302814 * A096293 A355049 A239549

Adjacent sequences: A088373 A088374 A088375 * A088377 A088378 A088379

Keyword

base,nonn

Author

Chuck Seggelin (barkeep(AT)plastereddragon.com), Nov 07 2003

Extensions

More terms (a(7) and a(8)) from Harvey P. Dale, May 03 2014

Status

approved