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Problems


IDDescription / Title
51
Prime digit replacements
52
Permuted multiples
53
Combinatoric selections
54
Poker hands
55
Lychrel numbers
56
Powerful digit sum
57
Square root convergents
58
Spiral primes
59
XOR decryption
60
Prime pair sets
61
Cyclical figurate numbers
62
Cubic permutations
63
Powerful digit counts
64
Odd period square roots
65
Convergents of e
66
Diophantine equation
67
Maximum path sum II
68
Magic 5-gon ring
69
Totient maximum
70
Totient permutation
71
Ordered fractions
72
Counting fractions
73
Counting fractions in a range
74
Digit factorial chains
75
Singular integer right triangles
76
Counting summations
77
Prime summations
78
Coin partitions
79
Passcode derivation
80
Square root digital expansion
81
Path sum: two ways
82
Path sum: three ways
83
Path sum: four ways
84
Monopoly odds
85
Counting rectangles
86
Cuboid route
87
Prime power triples
88
Product-sum numbers
89
Roman numerals
90
Cube digit pairs
91
Right triangles with integer coordinates
92
Square digit chains
93
Arithmetic expressions
94
Almost equilateral triangles
95
Amicable chains
96
Su Doku
97
Large non-Mersenne prime
98
Anagramic squares
99
Largest exponential
100
Arranged probability