OFFSET
0,1
COMMENTS
First differences of A052216 when the entries in that sequence are interpreted as base 3 numbers.
Can be regarded as a triangle, where T(0,0)=2, T(n+1,0) = T(n,0)+T(n,n), T(n+1,m) = T(n,m) for 0 < m <= n and T(n+1,n+1) = sum of T(n+1,0..n)
LINKS
G. C. Greubel, Table of n, a(n) for the first 50 rows
FORMULA
T(n,m) = 2*3^(m-1) = A025192(m) for m>0. T(n,0) = 2*A124302(n). - Franklin T. Adams-Watters, Sep 29 2011
EXAMPLE
triangle begins:
2
2 2
4 2 6
10 2 6 18
28 2 6 18 54
82 2 6 18 54 162
244 2 6 18 54 162 486.
MATHEMATICA
T[0, 0] := 2; T[n_, 0] := 3^(n - 1) + 1; T[n_, m_] := 2*3^(m - 1); Table[T[n, m], {n, 0, 5}, {m, 0, n}] (* G. C. Greubel, Oct 09 2016 *)
Join[{2}, Differences[Select[Range[50000], Total[IntegerDigits[#, 3]]==2&]]] (* Harvey P. Dale, Jul 04 2019 *)
CROSSREFS
KEYWORD
AUTHOR
Adam Shelly (adam.shelly(AT)gmail.com), Dec 04 2007, Dec 05 2007
EXTENSIONS
Edited by Franklin T. Adams-Watters, Sep 29 2011
STATUS
approved