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.

A347324 Row sums in A347738 when that sequence is written as a triangle.

Original entry on oeis.org

0, 2, 12, 48, 167, 541, 1692, 5187, 15700, 47030, 139986, 415385, 1230417, 3638657, 10744058, 31705658, 93563017, 276079102, 814408697, 2402076923, 7085491321, 20902994644, 61668276920, 181926014930, 536710980085, 1583529043750, 4672393755494, 13786612213841
Offset: 0

Views

Author

N. J. A. Sloane, Sep 13 2021

Keywords

Comments

Ratio of successive terms, a(n+1)/a(n), seems to be converging to ~2.9506. - Michael S. Branicky, Sep 19 2021

Examples

			Row 2 is 4,  3,  2,  2,  1,  0, which has sum 12.
		

Crossrefs

Cf. A347738, A003945 (row lengths).

Programs

  • Mathematica
    Total /@ TakeList[Import["https://oeis.org/A347738/b347738.txt", "Data"][[All, -1]], {1}~Join~Array[3*2^# &, 13, 0]] (* Michael De Vlieger, Sep 13 2021, generated using the b-file at A347738 *)
  • Python
    def afind():
        num, gte_inventory, rowsum, bigc = 0, [1], 0, 0
        print(0, end=", ")
        while True:
            c = gte_inventory[num] if num <= bigc else 0
            num += 1
            rowsum += c
            if c == 0:
                print(rowsum, end=", ")
                num = rowsum = 0
            for i in range(min(c, bigc)+1):
                gte_inventory[i] += 1
            for i in range(bigc+1, c+1):
                gte_inventory.append(1)
            bigc = len(gte_inventory) - 1
    afind() # Michael S. Branicky, Sep 19 2021

Extensions

a(14)-a(16) from Michael De Vlieger, Sep 13 2021
a(17)-a(27) from Michael S. Branicky, Sep 18 2021