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.

A140891 Binary encoding of the prime-ness of the 6 integers r+14*n with remainder r=1, 3, 5, 9, 11 or 13.

Original entry on oeis.org

9, 49, 20, 42, 41, 20, 27, 33, 62, 10, 39, 21, 11, 39, 60, 30, 49, 28, 43, 41, 28, 31, 49, 55, 14, 53, 53, 42, 51, 29, 14, 51, 22, 58, 45, 22, 59, 57, 55, 46, 37, 29, 11, 43, 60, 14, 53, 60, 42, 59, 54, 27, 43, 54, 26, 61, 29, 15, 39, 28, 31, 49, 23, 58, 47, 54, 27, 53, 62, 42
Offset: 0

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Author

Juri-Stepan Gerasimov, Jul 07 2008

Keywords

Comments

Classify all integers 14n+r with r= 1, 3, 5, 9, 11 or 13 as nonprime or prime and assign hit positions 0=LSB, 1, 2, 3, 4, 5=MSB to the 6 remainders in the same order. Raise the bit if 14n+r is nonprime, erase it if 14n+r is prime.
The sequence interprets this as a number in base 2 and shows the decimal representation.

Examples

			For n=2, the 6 numbers 29 (r=1), 31 (r=3), 33 (r=5), 37 (r=9), 39 (r=11) and 41 (r=13) are prime, prime, nonprime, prime, nonprime, prime, which is rendered into the binary 001010 = 2^2+2^4=4+16=20=a(2).
		

Crossrefs

Cf. A105052 (analog in base 10, prime = bit 1, remainder 1 = MSB), A140387 (analog in base 30, prime = bit 0, remainder 1 = LSB).

Programs

  • Mathematica
    f[n_]:=FromDigits[1-Boole[PrimeQ[({13,11,9,5,3,1}+14n)]],2]; Table[f[n],{n,0,100}] (* Ray Chandler, Feb 20 2009 *)

Extensions

Corrected and extended by Ray Chandler, Feb 20 2009