Search: id:A122953 Results 1-1 of 1 results found. %I A122953 %S A122953 1,2,2,3,3,4,3,4,4,4,5,6,6,6,4,5,5,5,6,6,5,7,7,8,8,8,8,9,9,8,5,6,6,6,7, %T A122953 6,7,8,8,8,8,6,8,10,9,10,9,10,10,10,10,11,10,10,11,12,12,12,12,12,12,10, %U A122953 6,7,7,7,8,7,8,9,9,8,7,9,10,10,11,11,10,10,10,10,11,9,7,11,11,13,13,12 %N A122953 a(n) = number of distinct positive integers represented in binary which are substrings of binary expansion of n. %C A122953 a(n) = A078822(n) if n is of the form 2^k - 1. Otherwise, a(n) = A078822(n) - 1. %C A122953 First occurrence of k: 1, 2, 4, 6, 11, 12, 22, 24, 28, 44, 52, 56, 88, 92, 112, 116, 186, 184, 220, 232, 244, 368, 376, 440, 472, ...,. %C A122953 Last occurrence of k: 2^n -1. %H A122953 Leroy Quet, Home Page (listed in lieu of email address) %e A122953 Binary 1 = 1, binary 2 = 10, binary 4 = 100 and binary 9 = 1001 are all substrings of binary 9 = 1001. So a(9) = 4. %t A122953 f[n_] := Length@ Select[ Union[ FromDigits /@ Flatten[ Table[ Partition[ IntegerDigits[n, 2], i, 1], {i, Floor[ Log[2, n] + 1]}], 1]], # > 0 &]; Array[f, 90] %Y A122953 Cf. A078822. %Y A122953 Sequence in context: A066412 A117119 A139141 this_sequence A128998 A137813 A003313 %Y A122953 Adjacent sequences: A122950 A122951 A122952 this_sequence A122954 A122955 A122956 %K A122953 nonn %O A122953 1,2 %A A122953 Leroy Quet Oct 25 2006 %E A122953 More terms from Robert G. Wilson v Nov 01 2006 Search completed in 0.001 seconds