OFFSET
0,2
LINKS
Mike Oakes, KingMovesForPrimes.
Zak Seidov, KingMovesForPrimes.
Zak Seidov et al., New puzzle? King moves for primes, digest of 28 messages in primenumbers group, Jul 13 - Jul 23, 2003. [Cached copy]
Sleephound, KingMovesForPrimes.
FORMULA
EXAMPLE
a(1)=9 because there are 9 cells in the 3 X 3 board;
a(2)=40 because from each of 4 corner cells, king can move to 3 cells, this gives 4*3=12 moves, from each of 4 side cells, king can move to 5 cells, this gives 4*5=20 moves and from the central cell, king can move to 8 cells, this gives 8 moves and the total is 12+20+8=40.
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Zak Seidov, Jul 17 2003
EXTENSIONS
Edited by Johannes W. Meijer, Jul 15 2010
STATUS
approved