A172321 Duplicate of A154689.

5, 7, 10, 13, 14, 18, 19, 26, 31, 38, 39, 43, 50, 55, 61, 62, 69, 72, 73, 78, 84, 86, 91, 95, 96, 98, 103, 108, 109, 110, 115, 119, 122, 123, 129, 133, 136, 138, 139, 145, 146, 151, 153, 159, 181, 182, 187, 190, 193, 199, 205

Offset

1,1

Comments

Numbers n such that d(n)=d(n-d(n)).

Links

Table of n, a(n) for n=1..51.

Mathematica

sndQ[n_]:=Module[{dn=DivisorSigma[0, n]}, dn==DivisorSigma[0, n-dn]]; Select[ Range[250], sndQ] (* Harvey P. Dale, Mar 05 2014 *)

Prog

(PARI) for(n=3, 1000, if(numdiv(n)==numdiv(n-numdiv(n)), print1(n, ", ")))

Crossrefs

Sequence in context: A218852 A028810 A097700 * A154689 A175766 A243187

Adjacent sequences: A172318 A172319 A172320 * A172322 A172323 A172324

Keyword

dead

Author

Juri-Stepan Gerasimov, Nov 20 2010

Status

approved