OFFSET
1,2
COMMENTS
The sequence lists the positive binomial coefficient predictors in base 4. For definition, see paper in link.
A subsequence of A089633.
LINKS
V. Shevelev, Binomial Coefficient Predictors, Journal of Integer Sequences, Vol. 14 (2011), Article 11.2.8
EXAMPLE
(767)_10 = (23333)_4 contains only digits 3, with the exception the leading digit which is 2. Therefore 767 is in the sequence.
(4091)_10 = (333323)_4 contains only digits 3, with the exception a digit 2.
MAPLE
isA188529 := proc(n) local dgs , n3, p, d; dgs := convert(n, base, 4); n3 := 0 ; for p from 1 to nops(dgs) do d := op(p, dgs) ; if d <> 3 then n3 := n3+1 ; if n3 >=2 then return false; end if; if p < nops(dgs) and d <> 2 then return false; end if; if p = nops(dgs) and d = 0 then return false; end if; end if; end do: return true; end proc:
A188529 := proc(n) option remember; local a; if n = 1 then 1; else for a from procname(n-1)+1 do if isA188529(a) then return a; end if; end do; end if; end proc:
seq(A188529(n), n=1..50) ; # R. J. Mathar, Apr 03 2011
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Vladimir Shevelev, Apr 03 2011
STATUS
approved