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.

A342032 Numbers with mutually distinct exponents in their prime factorization (A130091) with a record gap to the next term of A130091.

Original entry on oeis.org

1, 5, 13, 32, 200, 212, 1759, 2313, 5351, 16144, 51071, 128056, 159233, 630737, 1555349, 1627984, 2666309, 6838261, 12243457, 14619901, 25282087, 65891668, 78971281, 121377079, 543433039, 684779072, 1675445647, 2078471579, 2228572121, 11135788439, 42801667036
Offset: 1

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Author

Amiram Eldar, Feb 25 2021

Keywords

Comments

This sequence is infinite since the asymptotic density of A130091 is 0.
The corresponding values of the record gaps are 1, 2, 3, 5, 7, 11, 13, 20, 22, 29, 33, 40, 51, 55, 59, 67, 72, 82, 84, 87, 100, 121, 126, 132, 138, 147, 149, 150, 195, 209, 211, ...

Examples

			a(1) = 1 since both 1 and 1+1 = 2 are in A130091.
a(2) = 5 since 5 and 5+2 = 7 are in A130091 and 6 is not.
a(3) = 13 since 13 and 13+3 = 16 are in A130091 and 14 and 15 are not.
		

Crossrefs

Programs

  • Mathematica
    q[n_] := Length[(e = FactorInteger[n][[;; , 2]])] == Length[Union[e]]; seq = {}; m = 1; dm = 0; Do[If[q[n], d = n - m; If[d > dm, dm = d; AppendTo[seq, m]]; m = n], {n, 1, 10^6}]; seq