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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A253278 Congruentfree numbers: positive integers that are not divisible by any congruent number (A003273). 1
1, 2, 3, 4, 8, 9, 11, 16, 17, 19, 27, 32, 33, 43, 51, 57, 59, 64, 67, 73, 81, 83, 89, 97, 99, 107, 113, 121, 128, 129, 131, 139, 146, 153, 163, 171, 177, 178, 179, 187, 193, 201, 209, 211, 227, 233, 241, 243, 249, 251, 256, 267, 281, 283, 289, 292, 297, 307 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..58.

EXAMPLE

8 is in this sequence because the positive integer 8 is not divisible by any of the first 3 congruent numbers 5, 6, 7.

PROG

(PARI) isok(n, v) = {my(k=1); while (v[k] <= n, if (n % v[k] == 0, return (0)); k++; ); return (1); }

lista(nn) = {v = readvec("b003273.txt"); for (n=1, nn, if (isok(n, v), print1(n, ", ")); ); } \\ Michel Marcus, May 03 2015

CROSSREFS

Cf. A003273, A257604.

Sequence in context: A139461 A126421 A116111 * A184807 A032859 A032883

Adjacent sequences:  A253275 A253276 A253277 * A253279 A253280 A253281

KEYWORD

nonn

AUTHOR

Juri-Stepan Gerasimov, May 02 2015

EXTENSIONS

Corrected by Michel Marcus, May 03 2015. Edited by Wolfdieter Lang, May 05 2015

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 November 18 09:53 EST 2019. Contains 329261 sequences. (Running on oeis4.)