A268314 First term of a run of at least 11 consecutive integers which are not squarefree.

221167422, 1407472722, 3639720042, 3865964268, 4982931368, 5005996146, 7108776620, 8044261244, 10249558974, 12766690268, 13585489166, 19792784322, 26995377572, 30410811296, 30477326444, 32070270968, 34317891368, 39956560824, 40841363528, 42216508746, 43133805944, 46295514872, 47255689915

Offset

1,1

Comments

a(23) is the first term beginning a 12-chain. - Bill Hannaford, Oct 06 2016

Links

Table of n, a(n) for n=1..23.

Formula

A268314 = { A268313[k] | A268313[k+1] = A268313[k]+1 } = { A078143[k] | A078143[k+2] = A078143[k]+2 } = { A077647[k] | A077647[k+3] = A077647[k]+3 } = { A077640[k] | A077640[k+4] = A077640[k]+4 }.

Mathematica

s11[x_] := Apply[Plus, Table[Abs[MoebiusMu[x+j]], {j, 0, 10}]]; Do[If[Equal[s11[n], 0], Print[n]], {n, 10^8, 10^13}]

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), A268313 (10-chains).

Sequence in context: A250599 A114672 A268313 * A231630 A231092 A228965

Adjacent sequences: A268311 A268312 A268313 * A268315 A268316 A268317

Keyword

nonn

Author

M. F. Hasler, Feb 01 2016

Extensions

a(12)-a(23) from Bill Hannaford, Oct 06 2016

Status

approved