The product of 722*227 (163,894) contains neither 2 nor 7.
List all the couples (b,c; b>c) such that the product bcc*ccb contains neither b nor c.
Bonus: From the above list select couples, if any, using none of the corresponding digits in the partial products as well.
322 223 71806* 9 4 6**
722 227 163894* 49 4 14**
744 447 332568* 49 16 28
855 558 477090* 64 25 40
766 667 510922* 49 36 42
** shows partial products w/no
b,c
The code is uninteresting.
full candidate list:
100 1 100 1 0 0
200 2 400 4 0 0
300 3 900 9 0 0
400 4 1600 16 0 0
500 5 2500 25 0 0
600 6 3600 36 0 0
700 7 4900 49 0 0
800 8 6400 64 0 0
900 9 8100 81 0 0
211 112 23632 4 1 2
311 113 35143 9 1 3
411 114 46854 16 1 4
511 115 58765 25 1 5
611 116 70876 36 1 6
711 117 83187 49 1 7
811 118 95698 64 1 8
911 119 108409 81 1 9
322 223 71806* 9 4 6
422 224 94528 16 4 8
522 225 117450 25 4 10
622 226 140572 36 4 12
722 227 163894* 49 4 14
822 228 187416 64 4 16
922 229 211138 81 4 18
433 334 144622 16 9 12
533 335 178555 25 9 15
633 336 212688 36 9 18
733 337 247021 49 9 21
833 338 281554 64 9 24
933 339 316287 81 9 27
544 445 242080 25 16 20
644 446 287224 36 16 24
744 447 332568* 49 16 28
844 448 378112 64 16 32
944 449 423856 81 16 36
655 556 364180 36 25 30
755 557 420535 49 25 35
855 558 477090* 64 25 40
955 559 533845 81 25 45
766 667 510922* 49 36 42
866 668 578488 64 36 48
966 669 646254 81 36 54
877 778 682306 64 49 56
977 779 761083 81 49 63
988 889 878332 81 64 72
Edited on November 28, 2020, 7:43 am
soln
