A213240 Numbers n such that sum of digits of n = sum of digits of n’, where n’ is the arithmetic derivative of n.

4, 22, 27, 54, 56, 81, 94, 108, 121, 135, 166, 202, 216, 243, 245, 260, 265, 266, 272, 274, 308, 344, 346, 355, 382, 405, 445, 454, 459, 513, 517, 518, 526, 562, 567, 594, 634, 648, 675, 702, 706, 729, 784, 806, 832, 837, 841, 891, 913, 920, 922, 945, 950, 972

Offset

1,1

Links

Paolo P. Lava, Table of n, a(n) for n = 1..10000

Example

n=344 and 3+4+4=11; n’=524 and 5+2+4=11.

Maple

with(numtheory);
A213240:=proc(q)
local a, b, d, n, p, pfs;
for n from 1 to q do
  pfs:=ifactors(n)[2]; a:=n*add(op(2, p)/op(1, p), p=pfs); b:=0;
  while a>0 do b:=b+(a mod 10); a:=trunc(a/10); od;
  a:=n; d:=0; while a>0 do d:=d+(a mod 10); a:=trunc(a/10); od;
  if b=d then print(n); fi;
od; end:
A213240(100000000);

Crossrefs

Cf. A003415, A006753, A213239

Sequence in context: A059653 A022385 A244411 * A279314 A006753 A098836

Adjacent sequences: A213237 A213238 A213239 * A213241 A213242 A213243

Keyword

nonn,base

Author

Paolo P. Lava, Jun 07 2012

Status

approved