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.

A114180 Numbers n with mu(n) = mu(n+1) = mu(n+2).

Original entry on oeis.org

29, 33, 41, 48, 85, 93, 98, 101, 124, 137, 141, 201, 213, 217, 229, 242, 243, 281, 301, 342, 350, 393, 423, 429, 433, 445, 475, 548, 603, 617, 633, 641, 645, 697, 724, 741, 774, 821, 844, 845, 846, 869, 921, 969, 1021, 1024, 1041, 1085, 1129, 1137, 1189
Offset: 1

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Comments

Any sequence of 4 or more consecutive numbers with the same value for mu must all have mu(n)=0 (n divisible by a proper square) since at least one of every 4 consecutive numbers is divisible by 4.
A261890(a(n)) = 0. - Reinhard Zumkeller, Sep 05 2015

Examples

			mu(n)=1 for 33,34,35; 85,86,87; 93,94,95; ...
mu(n)=-1 for 29,30,31; 41,42,43; 101,102,103; ...
mu(n)=0 for 48,49,50; 98,99,100; 124,125,126; ...
		

Crossrefs

Union of A070258, A063838 and A070268. Cf. A008683, A070284.
Cf. A261890.

Programs

  • Haskell
    a114180 n = a114180_list !! (n-1)
    a114180_list = filter ((== 0) . a261890) [1..]
    -- Reinhard Zumkeller, Sep 05 2015
  • Mathematica
    SequencePosition[MoebiusMu[Range[1200]],{x_,x_,x_}][[;;,1]] (* Harvey P. Dale, Jul 23 2023 *)