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.

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A276375 Numbers n such that A240024(n + 1) = A002808(n).

Original entry on oeis.org

1, 2, 3, 11, 22, 29, 47, 49, 52, 67, 78, 79, 80, 91, 103, 104, 109, 111, 121, 130, 137, 148, 152, 159, 179, 184, 190, 200, 207, 215, 222, 241, 264, 278, 291, 307, 309, 316, 331, 336, 343, 347, 350, 361, 373, 380, 400, 409, 415, 430, 435, 445, 450, 453, 468
Offset: 1

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Author

Peter Kagey, Aug 31 2016

Keywords

Crossrefs

Programs

  • Haskell
    a276375 n = a276375_list !! (n - 1)
    a276375_list = filter (\i -> a240024 (i + 1) == a002808 i) [1..]
  • Mathematica
    c = Select[Range@ 600, CompositeQ]; a = {1, 4}; Do[k = 6; While[Or[PrimeQ@ k, MemberQ[a, k], CoprimeQ[a[[i - 1]], k]], k++]; AppendTo[a, k], {i, 3, Length@c + 1}]; Flatten@ Position[Union /@ Transpose@ {Rest@ a, c}, w_ /; Length@ w == 1] (* Michael De Vlieger, Sep 01 2016 *)
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