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%I #13 Oct 27 2023 22:00:45
%S 1,2,3,4,6,7,8,9,10,11,12,13,14,15,16,17,18,19,22,23,24,25,26,27,28,
%T 30,31,32,33,35,36,37,38,39,40,41,42,43,44,45,46,47,48,51,52,53,54,55,
%U 58,59,60,61,62,63,64,66,67,68,69,71,72,73,74,75,76,77,78,81,82,83,84,85
%N Numbers n such that A053238(n) = 2.
%H Reinhard Zumkeller, <a href="/A053241/b053241.txt">Table of n, a(n) for n = 1..10000</a>
%p with(numtheory): f := [seq( `if`((sigma(i) > sigma(i+1)),i,print( )), i=1..5000)];
%p seq( `if`(f[i+1] - f[i] = 2,i,print( )), i=1..100);
%o (Haskell)
%o import Data.List (elemIndices)
%o a053241 n = a053241_list !! (n-1)
%o a053241_list = map (+ 1) $ elemIndices 2 a053238_list
%o -- _Reinhard Zumkeller_, Oct 16 2011
%Y Cf. A000203, A053226, A053238, A053239, A053240 (complement), A053242, A053243, A053244, A053245.
%K nonn
%O 1,2
%A _Asher Auel_, Jan 10 2000
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