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.

A091020 Numbers n such that in binary representation n is a substring of the n-th prime.

Original entry on oeis.org

1, 5, 6, 15, 31, 32, 34, 39, 49, 50, 81, 82, 1052, 1799, 2119, 2573, 3378, 3447, 52225, 61870, 95752, 186157, 213547, 644695, 750550, 1414920, 2034869, 3768375, 4189897, 24628414, 50359121, 74288549, 87706569, 87706570
Offset: 1

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Author

Reinhard Zumkeller, Dec 14 2003

Keywords

Comments

A007088(a(n)) is a substring of A004676(a(n)).
The terms of A221860 \ {2,3} form a subsequence of this sequence.

Examples

			A000040(50) = 229: 50->110010, 229->11100101 = 1'110010'1, therefore 50 is a term.
prime(4189897) = 100001111111110111011001001[2] = 2^26 + 4189897. Apart from p=2 and p=3, this is the only prime below primepi(10^8) such that prime(p)-p = 2^k. See A221860 for further examples. - _M. F. Hasler_, Apr 10 2013
		

Crossrefs

Programs

  • Mathematica
    Select[Range[800000],SequenceCount[IntegerDigits[Prime[#],2],IntegerDigits[#,2]]>0&] (* The program generates the first 25 terms of the sequence. *) (* Harvey P. Dale, Nov 04 2024 *)

Formula

a(n) = A049084(A091021(n)), A000040(a(n)) = A091021(n).

Extensions

a(22)-a(34) from Donovan Johnson, May 08 2012