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.

A344185 a(n) = A344141(n) - 2^n.

Original entry on oeis.org

0, 3, 3, 3, 5, 3, 3, 27, 3, 9, 5, 9, 27, 33, 3, 43, 9, 9, 39, 9, 5, 3, 33, 27, 9, 27, 39, 3, 5, 3, 9, 141, 75, 27, 5, 53, 63, 99, 17, 57, 9, 39, 89, 33, 27, 3, 33, 45, 113, 29, 75, 9, 71, 125, 71, 149, 17, 99, 123, 3, 39, 105, 3, 27, 27, 9, 39, 163, 101, 43
Offset: 1

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Author

Jianing Song, May 11 2021

Keywords

Comments

A more intuitive version of A344141.
Every term other than the first is a member of A129771.
In A057496 it is stated that if x^n + x^3 + x^2 + x + 1 is irreducible, then so is x^n + x^3 + 1. It follows that no term can be equal to 15.
It is conjectured that no term can be of the form P_m(2^k), where P_m(x) = Product_{i>=0} (1 + x^(2^(d_i)))^(c_i) if the binary representation of m is m = Sum_{i>=0} c_i * 2^(d_i), k is an odd number. See my conjecture in A344177.

Examples

			See A344141.
		

Crossrefs

Programs

  • PARI
    A344185(n) = for(k=0, 2^n-1, if(polisirreducible(Mod(Pol(binary(2^n+k)), 2)), return(k)))