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.

A268313 First term of a run of at least 10 consecutive integers which are not squarefree.

Original entry on oeis.org

221167422, 221167423, 262315467, 363504972, 463239475, 1202800371, 1407472722, 1407472723, 1557947844, 1609077723, 1911823144, 2217728772, 2695179044, 2737800168, 2847305571, 3639720042, 3639720043, 3672883247, 3865964268, 3865964269, 3982659575, 4246929267, 4818537743, 4982931368
Offset: 1

Views

Author

M. F. Hasler, Feb 01 2016

Keywords

Crossrefs

Cf. A013929, A045882 (first of the k-chains), A051681.
Cf. A068781 (2-chains), A070258 (3-chains), A070284 (4-chains), A078144 (5-chains), A049535 (6-chains), A077640 (7-chains), A077647 (8-chains), A078143 (9-chains), A268314 (11-chains).

Programs

  • Mathematica
    s10[x_] := Apply[Plus, Table[Abs[MoebiusMu[x+j]], {j, 0, 9}]]; Do[If[Equal[s10[n], 0], Print[n]], {n, 10^8, 10^10}]

Formula

A268313 = { A078143[k] | A078143[k+1] = A078143[k]+1 } = { A077647[k] | A077647[k+2] = A077647[k]+2 } = { A077640[k] | A077640[k+3] = A077640[k]+3 }.