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%I #13 Aug 16 2022 10:18:15
%S 1,2,3,4,6,5,11,7,8,9,23,10,31,15,13,12,58,14,74,16,18,29,122,17,25,
%T 40,21,22,224,19,267,20,38,69,33,24,453,89,49,26,636,28,737,43,30,141,
%U 995,27,53,35,84,57,1523,34,59,36,108,257,2244,32,2528,310,41,37,77,52
%N Inverse permutation to A053212.
%C a(n) is the index of A005179(n) in A007416; equivalently, a(n) is the number of minimal numbers (numbers in A007416) that are <= A005179(n). - _Jianing Song_, Aug 16 2022
%H <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a>
%e a(23) = 122 because d(n) (A000005(n)) takes 121 different values before it first reaches 23 (at n = 2^22).
%o (Haskell)
%o import Data.List (elemIndex); import Data.Maybe (fromJust)
%o a064787 = (+ 1) . fromJust . (`elemIndex` a053212_list)
%o -- _Reinhard Zumkeller_, Apr 18 2015
%Y Cf. A053212, A005179, A007416, A000005.
%K easy,nonn
%O 1,2
%A _N. J. A. Sloane_, Oct 20 2001
%E More terms from _Naohiro Nomoto_, Oct 31 2001
%E More terms from _David Wasserman_, Aug 14 2002
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