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 A243617 Numbers whose sum of digits equals the number of bits in its binary expansion. No zeros allowed in the digital expansion. 2

%I

%S 1,2,13,23,33,42,51,115,124,134,143,152,161,215,224,233,242,251,261,

%T 315,324,333,342,351,414,423,432,441,514,523,532,541,613,622,631,712,

%U 721,811,1118,1127,1136,1145,1154,1163,1172,1181,1217,1226,1235,1244

%N Numbers whose sum of digits equals the number of bits in its binary expansion. No zeros allowed in the digital expansion.

%C This sequence is a subsequence of A243615.

%H Andreas Boe, <a href="/A243617/b243617.txt">Table of n, a(n) for n = 1..10000</a>

%e 42 -> 4+2=6, 42=101010_2 -> 6 bits.

%o (PARI) isok(n) = (sumdigits(n) == #binary(n)) && (vecmin(digits(n)) != 0); \\ _Michel Marcus_, Jun 08 2014

%Y Cf. A243615 (same principle, but zeros allowed in digital expansion).

%K nonn,base

%O 1,2

%A _Andreas Boe_, Jun 07 2014

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Last modified June 21 19:12 EDT 2021. Contains 345365 sequences. (Running on oeis4.)