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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A332952 Squarefree semiprimes which never occur in A245486.

Original entry on oeis.org

46, 58, 74, 94, 106, 118, 122, 134, 142, 158, 166, 194, 202, 206, 214, 262, 267, 274, 278, 298, 309, 314, 326, 334, 339, 346, 358, 362
Offset: 1

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Author

Jinyuan Wang, Mar 04 2020

Keywords

Comments

Also squarefree semiprimes which never occur in A332951.
This sequence is infinite. It appears that all terms can be divisible by 2 or 3.
If A014664(i) = A014664(j) for some 1 < i < j, then 2*prime(i) is a term. See A245486 for more information.

Examples

			a(2) = 58 because when 2^m - 1 or 2^m + 1 is divisible by 29, it's also divisible by 113. Therefore, there's no integer k such that A245486(k) = A006530(k) * A006530(k+1) = 58.

Links

  • Romanian Master in Mathematics Contest, Bucharest, 2020, Problem 6

Crossrefs

Cf. A000040, A006530, A006881, A014664, A245486, A332951.
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