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.

A073849 Cumulative sum of initial digits of (n base 3).

Original entry on oeis.org

0, 1, 3, 4, 5, 6, 8, 10, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 68, 70, 72, 74, 76, 78, 80, 82, 84, 86, 88, 90, 92
Offset: 0

Views

Author

Jonathan Vos Post, Aug 28 2005

Keywords

Examples

			    n in   init  cumulative
n  base 3   dgt     sum
-  ------  ----  ----------
0     0      0       0
1     1      1       1
2     2      2       3
3    10      1       4
4    11      1       5
5    12      1       6
		

Crossrefs

Programs

  • Mathematica
    Accumulate[Table[First[IntegerDigits[n,3]],{n,0,80}]] (* Harvey P. Dale, Mar 24 2015 *)
  • PARI
    lista(nn) = {s = 0; print1(s, ", "); for (n=1, nn, s += digits(n,3)[1]; print1(s, ", "););} \\ Michel Marcus, Mar 24 2015

Formula

a(n) = Sum_{i=0..n} A000030(A007089(n)).

Extensions

Corrected by Harvey P. Dale, Mar 24 2015