login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A246449 Numbers n such that no cube can end in n (in the sense of the respective decimal expansions). 3
10, 14, 15, 18, 20, 22, 26, 30, 34, 35, 38, 40, 42, 45, 46, 50, 54, 55, 58, 60, 62, 65, 66, 70, 74, 78, 80, 82, 85, 86, 90, 94, 95, 98, 100, 102, 105, 106, 108, 110, 114, 115, 116, 118, 120, 122, 124, 126, 130, 132, 134, 135, 138, 140, 142, 145, 146, 148, 150, 154, 155 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Complement of A246422.

The terms with n digits are the complement in [10^(n-1) .. 10^n-1] of the set of residues of k^3 mod 10^n for 10^((n-1)/3) < k < 10^n. - M. F. Hasler, Jan 26 2020

LINKS

Robert Israel, Table of n, a(n) for n = 1..10000

MAPLE

seq(op(sort(convert({$10^(d-1)..10^d-1} minus map(t -> t^3 mod 10^d, {$0..10^d-1}), list))), d=1..3); # Robert Israel, Jan 26 2020

PROG

(PARI) v=vector(1000); for(k=1, 10^4, my(q=k^3, w=digits(q)); for(j=0, 2, v[1+fromdigits(w[#w-j..#w])]++)); for(k=1, 160, if(v[k]==0, print1(k-1, ", "))) \\ Hugo Pfoertner, Jan 26 2020

(PARI) A246449_row(n)=setminus([10^(n-1)..10^n-1], Set([k^3|k<-[sqrtnint(10^(n-1), 3)+1..10^n-1]]%10^n)) \\ Yields the n-digit terms. - M. F. Hasler, Jan 26 2020

CROSSREFS

Cf. A246422.

Sequence in context: A102361 A280032 A227010 * A121836 A317590 A081062

Adjacent sequences:  A246446 A246447 A246448 * A246450 A246451 A246452

KEYWORD

nonn,base

AUTHOR

Derek Orr, Aug 26 2014

EXTENSIONS

Corrected by Robert Israel, Jan 26 2020

Name edited and incorrect PARI program deleted by M. F. Hasler, Jan 26 2020

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 May 8 02:26 EDT 2021. Contains 343652 sequences. (Running on oeis4.)