1. Quadruple Sudoku Tony Sudbery

2. 1 1 1 1 1 1 1 1 1

22. 1 1 1 1 1 1 1 1 1

23. 1 1 1 1 1 1 1 1 1

24. 1 1 1 1 1 1 1 1 1

25. 1 1 1 1 1 1 1 1 1

26. 1 1 1 1 1 1 1 1 1

27. 1 1 1 1 1 1 1 1 1

28. 1 1 1 1 1 1 1 1 1

29. 1 1 1 1 1 1 1 1 1

30. 1 1 1 1 1 1 1 1 1

31. 1 1 1 1 1 1 1 1 1

32. 1 1 1 1 1 1 1 1 1

33. 1 1 1 1 1 1 1 1 1

34. 1 1 1 1 1 1 1 1 1

35. 1 1 1 1 1 1 1 1 1

36. 1 1 1 1 1 1 1 1 1

37. 1 1 1 1 1 1 1 1 1

38. 1 1 1 1 1 1 1 1 1

39. 1 1 1 1 1 1 1 1 1

40. 11 1 1 1 1 1 1 1

41. 1 1 1 1 1 1 1 1 1

42. 1 1 1 1 1 1 1 1 1

43. 123897645 456231978 789564312 978456231 312789564 645123897 564312789 897645123 231978456

44. 123897645 456231978 789564312 978456231 312789564 645123897 564312789 897645123 231978456

45. 123897645 456231978 789564312 978456231 312789564 645123897 564312789 897645123 231978456

46. 123897645 456231978 789564312 978456231 312789564 645123897 564312789 897645123 231978456

47. Baby Sudoku Challenge: Can you set a 2x2x2x2 quadruple Sudoku?

49. Baby Sudoku Challenge: Can you set a 2x2x2x2 quadruple Sudoku? If not, why not?

51. Dürer’s übermagic square 163213 510118 96712 415141

52. 163213 510118 96712 415141 163213 510118 96712 415141 163213 510118 96712 415141 163213 510118 96712 415141 163213 510118 96712 415141 163213 510118 96712 415145 163213 510118 96712 415141 163213 510118 96712 415141 163213 510118 96712 415141 163213 510118 96712 415141 163213 510118 96712 415141 163213 510118 96712 415141

53. There are 86 4-element subsets of {1,…,16} which sum to 34. 52 of these are plane squares in 4D Number which are not plane squares = 34 Number listed by Alex Bellos = 34

57. Baby Sudoku Challenge: Can you set a 2x2x2x2 quadruple Sudoku?