(35S) Ulam Spiral Programme - Printable Version +- HP Forums (https://www.hpmuseum.org/forum) +-- Forum: HP Software Libraries (/forum-10.html) +--- Forum: General Software Library (/forum-13.html) +--- Thread: (35S) Ulam Spiral Programme (/thread-2561.html) |
(35S) Ulam Spiral Programme - Gerald H - 12-05-2014 08:13 AM For integer entry N > 1 the programme returns the two difficult non-diagonal neighbours of N 1 LBL U 2 STO N 3 4 4 * 5 2 6 - 7 IP(SQRT(REGX)) 8 2*REGX 9 STO K 10 R↓ 11 x<>y 12 4 13 - 14 SQRTx 15 IP 16 x<y? 17 -K►K 18 N-K+3 19 N+ABS(K)+5 20 RTN The spiral begins 10 .... 09 2 3 08 1 4 07 6 5 So for entry 2 the programme returns 9 & 11. |