A273799 Numbers n such that the decimal digits of n-phi(n) are a permutation of those of n.

91, 342, 351, 627, 684, 874, 950, 1824, 2114, 2318, 2715, 3051, 3171, 3172, 3402, 3411, 4228, 6344, 6804, 7346, 8414, 8456, 8474, 9093, 9125, 9191, 9254, 9500, 9531, 9548, 9672, 9824, 9950, 15804, 18010, 18312, 18508, 18930, 19190, 21028, 22126, 23218, 24180, 24716

Offset

1,1

Links

Paolo P. Lava, Table of n, a(n) for n = 1..1000

Example

91 - phi(91) = 91 - 72 = 19;
342 - phi(342) = 342 - 108 = 234.

Maple

with(numtheory): P:=proc(q) local a, b, c, d, k, n; for n from 1 to q do a:=n; b:=n-phi(n);
if ilog10(a)=ilog10(b) then c:=[]; d:=[]; for k from 1 to ilog10(n)+1 do
c:=[op(c), (a mod 10)]; a:=trunc(a/10); d:=[op(d), (b mod 10)]; b:=trunc(b/10); od;
c:=sort(c); d:=sort(d); if c=d then print(n); fi; fi; od; end: P(10^25);

Mathematica

Select[Range[25000], Sort@ IntegerDigits@ # == Sort@ IntegerDigits[# - EulerPhi@ #] &] (* Michael De Vlieger, Jun 01 2016 *)

Crossrefs

Cf. A051953, A115921.

Sequence in context: A350206 A020441 A209255 * A063137 A234131 A234124

Adjacent sequences: A273796 A273797 A273798 * A273800 A273801 A273802

Keyword

nonn,easy,base

Author

Paolo P. Lava, May 31 2016

Status

approved