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

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A208646 Calendar Problem #27, April 2012 Mathematics Teacher. 0
 9861, -1986, 9681, -1896, 8961, -1968, 8691, -1698 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS The numbers are paired on the basis of rotational symmetry with alternating signs. LINKS Margaret Coffey, Editor, Calendar Problem #27, April 2012 Mathematics Teacher, pp. 521, 524. EXAMPLE If you rotate the first number, 9861, 180 degrees about its center, and put a negative sign in front, you get the second number: -1986. Similarly, the third and fourth numbers are rotations of each other, as well as of the fifth and sixth numbers.  Therefore the eighth number is the rotation and negation of the seventh number, 8961, which would be -1698. CROSSREFS Cf. A045574, A054047. Sequence in context: A022199 A203809 A257299 * A001230 A238076 A103810 Adjacent sequences:  A208643 A208644 A208645 * A208647 A208648 A208649 KEYWORD sign,easy,base AUTHOR Jonathan Vos Post, Mar 01 2012 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.

Last modified June 6 18:59 EDT 2020. Contains 334832 sequences. (Running on oeis4.)