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.

Showing 1-2 of 2 results.

A348674 Number of distinct values that can be produced by splitting n and adding the parts.

Original entry on oeis.org

1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 4
Offset: 0

Views

Author

Alois P. Heinz, Oct 29 2021

Keywords

Comments

Differs from A055642 first at n=120: a(120) = 4 != 3 = A055642(120).
The number of split positions can vary from 0 to length(n)-1.

Examples

			a(0) = 1: 0.
a(10) = 2: 1 = 1+0, 10.
a(100) = 3: 1 = 1+0+0, 10 = 10+0, 100.
a(120) = 4: 3 = 1+2+0, 12 = 12+0, 21 = 1+20, 120.
a(2493690) = 62 = |{33, 51, 60, 69, 78, 87, 96, 105, 114, 123, 132, 141, 150, 159, 168, 177, 186, 195, 213, 267, 294, 321, 348, 375, 384, 402, 420, 510, 564, 591, 618, 708, 726, 744, 789, 807, 942, 951, 969, 1032, 1050, 1185, 2508, 2562, 2589, 3183, 3705, 3723, 3741, 3939, 4947, 5028, 9375, 9393, 24945, 25026, 49371, 93696, 93714, 249369, 493692, 2493690}|.
		

Crossrefs

Ordinal transform gives A349315.
Where records occur: A349316.

Programs

  • Maple
    b:= proc(s) option remember; (n-> {parse(s), seq(seq(seq(x+y,
          y=b(s[i+1..n])), x=b(s[1..i])), i=1..n-1)})(length(s))
        end:
    a:= n-> nops(b(""||n)):
    seq(a(n), n=0..120);

Formula

a(n) <= 2^floor(log_10(n)) = 2^A004216(n) for n>0.
a((10^n-1)/9) = a(A002275(n)) <= A000041(n) with equality only for n <= 23.
a(10^n) = a(A011557(n)) = n+1.

A349316 Where records occur in A348674.

Original entry on oeis.org

0, 10, 100, 120, 1010, 1020, 1120, 1230, 10120, 10130, 10230, 10240, 11230, 11240, 12240, 12350, 101130, 101240, 101350, 102240, 102350, 102460, 112240, 112350, 112460, 122360, 122470, 123470, 123580, 1011240, 1011250, 1011350, 1011360, 1012250, 1012360, 1012460
Offset: 1

Views

Author

Alois P. Heinz, Nov 14 2021

Keywords

Crossrefs

Programs

  • Maple
    b:= proc(s) option remember; (n-> {parse(s), seq(seq(seq(x+y,
          y=b(s[i+1..n])), x=b(s[1..i])), i=1..n-1)})(length(s))
        end:
    a:= proc(n) option remember; local k, t; t:=nops(b(""||(a(n-1))));
          for k from 1+a(n-1) while nops(b(""||k))<=t do od; k
        end: a(1):=0:
    seq(a(n), n=1..29);

Formula

A349315(a(n)) = 1.
A348674(a(n)) < A348674(a(n+1)).
Showing 1-2 of 2 results.