login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A305892 a(n) = 1 if n is composite and the n-th Stern polynomial B(n,x) is irreducible, 0 otherwise. 2
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1 (list; graph; refs; listen; history; text; internal format)
OFFSET

1

COMMENTS

Characteristic function for A186892, apart from its initial term.

See also A186891 about related Ulas & Ulas conjecture.

LINKS

Antti Karttunen, Table of n, a(n) for n = 1..65537

Index entries for characteristic functions

FORMULA

a(n) = (1-A010051(n))*A283991(n).

PROG

(PARI)

ps(n)=if(n<2, n, if(n%2, ps(n\2)+ps(n\2+1), 'x*ps(n\2)));

A305892(n) = (!isprime(n) && polisirreducible(ps(n))); \\ Antti Karttunen, Jun 16 2018, after Charles R Greathouse IV's Apr 07 2015 code for A186892.

CROSSREFS

Cf. A010051, A186891, A186892, A283991, A284011.

Differs from A305821 for the first time at n=65, where a(65) = 1, while A305821(65) = 0.

Sequence in context: A011739 A023975 A305821 * A324870 A011738 A011737

Adjacent sequences:  A305889 A305890 A305891 * A305893 A305894 A305895

KEYWORD

nonn

AUTHOR

Antti Karttunen, Jun 16 2018

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified October 19 11:09 EDT 2019. Contains 328216 sequences. (Running on oeis4.)