Search: id:A004956 Results 1-1 of 1 results found. %I A004956 %S A004956 0,2,4,5,7,9,10,12,13,15,17,18,20,22,23,25,26,28,30,31, %T A004956 33,34,36,38,39,41,43,44,46,47,49,51,52,54,56,57,59,60, %U A004956 62,64,65,67,68,70,72,73,75,77,78,80,81,83,85,86,88,89 %N A004956 Ceiling of n*phi, phi = (1+sqrt(5))/2. %C A004956 a(0)=0, a(1)=2; for n>1, a(n)=a(n-1)+2 if n is already in the sequence, a(n)=a(n-1)+1 otherwise. %C A004956 Integer solutions to the equation x=ceiling(phi*floor(x/phi)) - Benoit Cloitre (benoit7848c(AT)orange.fr), Feb 14 2004 %C A004956 Benoit Cloitre, Mar 05 2007: (Start) The following is an alternative way to obtain this sequence. NP means "term not in parentheses". Write down the natural numbers and mark the least NP, which is 1: %C A004956 1* 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 ... %C A004956 Take the 1st NP (which is 1) and parenthesize it; mark the least NP (which is 2): %C A004956 (1*) 2* 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 ... %C A004956 Take the 2nd NP (which is 3) and parenthesize it; mark the next NP (which is 4): %C A004956 (1*) 2* (3) 4* 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 ... %C A004956 Take the 4th NP (which is 6) and parenthesize it; mark the next NP (which is 5): %C A004956 (1*) 2* (3) 4* 5* (6) 7 8 9 10 11 12 13 14 15 16 17 18 19 ... %C A004956 Continuing in this way we obtain %C A004956 (1*) 2* (3) 4* 5* (6) 7* (8) 9* 10* (11) 12* 13* (14) 15* (16) 17* (18) 19* ... %C A004956 The starred entries (after the first) give the sequence. (End) %H A004956 B. Cloitre, N. J. A. Sloane and M. J. Vandermast, Numerical analogues of Aronson's sequence, J. Integer Seqs., Vol. 6 (2003), #03.2.2. %H A004956 B. Cloitre, N. J. A. Sloane and M. J. Vandermast, Numerical analogues of Aronson's sequence (math.NT/0305308) %Y A004956 Essentially same as A026351. %Y A004956 Sequence in context: A026463 A087063 A047497 this_sequence A026351 A047212 A121347 %Y A004956 Adjacent sequences: A004953 A004954 A004955 this_sequence A004957 A004958 A004959 %K A004956 nonn,easy %O A004956 0,2 %A A004956 N. J. A. Sloane (njas(AT)research.att.com). Search completed in 0.001 seconds