A070240 is duplicate of A007369

[Max]

First of all, I've verified the sequence A070240 and found that the current last term "40" should not be present in the sequence.
Second, it is easy to see that the procedure described at A070240 is nothing more than just sieving the values of A007369 out of the sequence of positive integers. It is very similar to the Sieve of Eratosthenes sieving the prime numbers.

So besides the first (artificially introduced) term "1", the sequence A070240 is a duplicate of A007369.
I think there is no much sense to keep it as a separate sequence.

Max



ID Number: A007369 (Formerly M1355)
URL:       http://www.research.att.com/projects/OEIS?Anum=A007369
Sequence:  2,5,9,10,11,16,17,19,21,22,23,25,26,27,29,33,34,35,37,41,43,
            45,46,47,49,50,51,52,53,55,58,59,61,64,65,66,67,69,70,71,73,
            75,76,77,79,81,82,83,85,86,87,88,89,92,94,95,97,99,100,101,
            103,105,106,107,109,111,113
Name:      Numbers n such that sigma (x) = n has no solution.
References M. Abramowitz and I. A. Stegun, eds., Handbook of Mathematical
               Functions, National Bureau of Standards Applied Math. Series 55, 1964
               (and various reprintings), p. 840.
Example:   a(4) = 10 because there is no x < 10 whose sigma(x) = 10.
Math'ca:   a = {}; Do[s = DivisorSigma[1, n]; a = Append[a, s], {n, 1, 115} ];
               Complement[ Table[ n, {n, 1, 115} ], Union[a] ]
See also:  Sequence in context: A002580 A091656 A070240 this_sequence A100530
               A055394 A078360
            Adjacent sequences: A007366 A007367 A007368 this_sequence A007370
               A007371 A007372
Keywords:  nonn
Offset:    1
Author(s): njas, Mira Bernstein, Robert G. Wilson v (rgwv(AT)rgwv.com)
Extension: More terms from David Wison

ID Number: A070240
URL:       http://www.research.att.com/projects/OEIS?Anum=A070240
Sequence:  1,2,5,9,10,11,16,17,19,21,22,23,25,26,27,29,33,34,35,37,40
Name:      a(n) is constructed inductively in stages from the list L =
               {1,2,3,....} by the following sieve procedure. Stage 1. Add 1 as the
               first term of the sequence a(n), and strike off 1 from L. Stage n+1. Add
               the first (i.e. leftmost) term k of L as a new term of the sequence a(n),
               and strike off k, sigma(k), sigma(sigma(k)),.... from L.
See also:  Sequence in context: A020820 A002580 A091656 this_sequence A007369
               A100530 A055394
            Adjacent sequences: A070237 A070238 A070239 this_sequence A070241
               A070242 A070243
Keywords:  nonn
Offset:    1
Author(s): Joseph L. Pe (joseph_l_pe(AT)hotmail.com), May 08 2002