cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A136401 a(n) = 3*a(n-1) - 4*a(n-2) + 6*a(n-3) - 4*a(n-4), with initial terms 0,0,0,1.

Original entry on oeis.org

0, 0, 0, 1, 3, 5, 9, 21, 45, 85, 165, 341, 693, 1365, 2709, 5461, 10965, 21845, 43605, 87381, 174933, 349525, 698709, 1398101, 2796885, 5592405, 11183445, 22369621, 44741973, 89478485, 178951509, 357913941, 715838805, 1431655765, 2863289685, 5726623061
Offset: 0

Views

Author

Paul Curtz, Mar 30 2008

Keywords

Examples

			Binary.................Decimal
0............................0
0............................0
0............................0
1............................1
11...........................3
101..........................5
1001.........................9
10101.......................21
101101......................45
1010101.....................85
10100101...................165
101010101..................341
1010110101.................693
10101010101...............1365
101010010101..............2709
1010101010101.............5461
10101011010101...........10965
101010101010101..........21845
1010101001010101.........43605, etc. - _Philippe Deléham_, Mar 21 2014
		

Crossrefs

Cf. A154957.

Programs

  • Mathematica
    CoefficientList[Series[x^3/((x - 1) (2 x - 1) (2 x^2 + 1)), {x, 0, 40}], x] (* Vincenzo Librandi, Mar 22 2014 *)
    LinearRecurrence[{3,-4,6,-4},{0,0,0,1},40] (* Harvey P. Dale, Mar 13 2018 *)

Formula

a(n+3) = Sum_{k=0..n} A154957(n,k)*2^k. - Philippe Deléham, Mar 21 2014
G.f.: x^3/((x-1)*(2*x-1)*(2*x^2+1)). - Philippe Deléham, Mar 21 2014

Extensions

More terms from Philippe Deléham, Mar 21 2014