A164943 - OEIS

%I #6 May 31 2019 17:28:16

%S 1,7,61,495,7929,126875,2030013,32480223,1039367153,33259748915,

%T 1064311965301,34057982889655,1089855452468985,34875374479007547,

%U 1116011983328241533,35712383466503729087,2285592541856238661601

%N Decimal value of the concatenation of first n odd numbers in binary.

%H Harvey P. Dale, <a href="/A164943/b164943.txt">Table of n, a(n) for n = 1..383</a>

%e a(3)=61 because the first 3 odd numbers in binary are 1 11 101, and the concatenation 111101 in base 10 = 61. a(4)=495 because the first 4 odd numbers in binary are 1 11 101 111, and the concatenation 111101111 in base 10 = 495.

%t Table[FromDigits[Flatten[IntegerDigits[Range[1,2n+1,2],2]],2],{n,0,20}] (* _Harvey P. Dale_, May 31 2019 *)

%K base,easy,nonn

%O 1,2

%A _Gil Broussard_, Sep 01 2009