A233465 Numbers n such that sigma(n) = reversal(2n).

1259196, 1473381

Offset

1,1

Comments

a(3) > 10^12. - Giovanni Resta, Mar 15 2014

Links

Table of n, a(n) for n=1..2.

Mathematica

rev[n_] := FromDigits@ Reverse@ IntegerDigits@n; Select[Range[2*10^6], DivisorSigma[1, #] == rev[2*#] &] (* Giovanni Resta, Mar 15 2014 *)

Crossrefs

Cf. A000203, A004086, A233467.

Sequence in context: A186089 A208489 A257268 * A250596 A250825 A292217

Adjacent sequences: A233462 A233463 A233464 * A233466 A233467 A233468

Keyword

nonn,base,more,bref

Author

Farideh Firoozbakht, Mar 14 2014

Status

approved