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.

A347756 Local minima in A347113.

Original entry on oeis.org

1, 2, 3, 7, 11, 17, 19, 23, 31, 37, 59, 61, 67, 79, 97, 151, 157, 199, 211, 229, 271, 307, 337, 367, 499, 577, 601, 619, 691, 727, 829, 877, 937, 1009, 1237, 1279, 1297, 1399, 1459, 1531, 1609, 1657, 1867, 2011, 2029, 2089, 2131, 2137, 2179, 2281, 2311, 2467, 2539
Offset: 1

Views

Author

Michael De Vlieger, Sep 12 2021

Keywords

Comments

Distinct terms in A347755.
Conjecture: subset of A008578.

Crossrefs

Programs

  • Mathematica
    Block[{nn = 2^13, a = {1}, c, k, m, u = 2, v}, v = a; Map[Set[c[#], 1] &, Union@ a]; Do[Set[k, u]; If[PrimeQ[#], m = 2; While[IntegerQ[c[m #]], m++]; k = m #, While[Or[IntegerQ[c[k]], k == #, GCD[k, #] == 1], k++]] &[a[[-1]] + 1]; AppendTo[a, k]; Set[c[k], 1]; AppendTo[v, u]; If[k == u, While[IntegerQ[c[u]], u++]], nn]; Union@ v]
    (* or using A347113 bfile: *)
    Block[{a, u = {1}, v = 1}, a = Import["https://oeis.org/A347113/b347113.txt", "Data"][[All, -1]]; Do[If[a[[i]] == v, While[! FreeQ[a[[1 ;; i]], v], v++]]; AppendTo[u, v], {i, Length[a]}];  Union@ u]
  • Python
    from math import gcd
    A347756_list, nset, m, j = [1], {1}, 2, 2
    for _ in range(10**4):
        k = m
        while k == j or gcd(k,j) == 1 or k in nset:
            k += 1
        j = k + 1
        nset.add(k)
        if k == m:
            A347756_list.append(k)
        while m in nset:
            m += 1 # Chai Wah Wu, Sep 13 2021

Formula

A347757(n) = index of a(n) in A347113.