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A087093 Numbers n such that n and its digit reversal have the same number of divisors, but different prime signatures. 0
24, 42, 264, 288, 462, 658, 856, 882, 1071, 1128, 1314, 1464, 1701, 2058, 2130, 2132, 2312, 2324, 2424, 2510, 2590, 2616, 2664, 2744, 2765, 2782, 2786, 2872, 2904, 2938, 2975, 3159, 3194, 4010, 4090, 4092, 4094, 4125, 4131, 4136, 4168, 4184, 4220, 4228 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Terms in A062895 but not in A085869.

LINKS

Table of n, a(n) for n=1..44.

EXAMPLE

24 and 42 are members as 24 and 42 each have 8 divisors but with different prime signatures.

MATHEMATICA

psQ[n_]:=Sort[Transpose[FactorInteger[n]][[2]]]!=Sort[Transpose[ FactorInteger[FromDigits[Reverse[IntegerDigits[n]]]]][[2]]]; ndQ[n_]:= DivisorSigma[0, n]==DivisorSigma[0, FromDigits[Reverse[ IntegerDigits[ n]]]]; Select[Range[5000], psQ[#]&&ndQ[#]&] (* Harvey P. Dale, Nov 11 2011 *)

CROSSREFS

Cf. A085869, A085870.

Sequence in context: A039411 A043234 A044014 * A118299 A302360 A258865

Adjacent sequences:  A087090 A087091 A087092 * A087094 A087095 A087096

KEYWORD

nonn,base

AUTHOR

Ray Chandler, Aug 09 2003

STATUS

approved

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Last modified March 30 12:10 EDT 2020. Contains 333125 sequences. (Running on oeis4.)