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Positions at which powers of 2 occur in A051145.
3

%I #11 Oct 09 2022 09:42:43

%S 1,2,3,5,6,9,12,17,29,45,48,81,105,108,177,245,323,324,569,648,893,

%T 1277,1296,2121,2592,3221,4853,5184,7697,11015,15333,15552,25841,

%U 31104,40157,59213,84239,93312,135107,184679,265277,279936,445029,606509,830411,839808

%N Positions at which powers of 2 occur in A051145.

%C A209229(A051145(a(n))) = 1;

%C the definition of this sequence was the original definition of A051147.

%H Rémy Sigrist, <a href="/A244747/a244747_1.txt">C++ program</a>

%o (Haskell)

%o import Data.List (findIndices)

%o a244747 n = a244747_list !! (n-1)

%o a244747_list = findIndices ((== 1) . a209229) a051145_list

%o (C++)

%o See Links section.

%Y Cf. A209229, A051147 (subsequence).

%K nonn

%O 1,2

%A _Reinhard Zumkeller_, Jul 05 2014

%E More terms from _Rémy Sigrist_, Oct 09 2022