(cache) Archived Problems

Problems Archives

The problems archives table shows problems 1 to 594. If you would like to tackle the 10 most recently published problems then go to Recent problems.
Click the description/title of the problem to view details and submit your answer.

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ID	Description / Title	Solved By
1	Multiples of 3 and 5	660568
2	Even Fibonacci numbers	534285
3	Largest prime factor	383903
4	Largest palindrome product	343317
5	Smallest multiple	353239
6	Sum square difference	355241
7	10001st prime	304316
8	Largest product in a series	258781
9	Special Pythagorean triplet	260602
10	Summation of primes	239294
11	Largest product in a grid	174677
12	Highly divisible triangular number	162401
13	Large sum	168272
14	Longest Collatz sequence	167197
15	Lattice paths	138536
16	Power digit sum	169915
17	Number letter counts	113300
18	Maximum path sum I	109277
19	Counting Sundays	101383
20	Factorial digit sum	150113
21	Amicable numbers	109134
22	Names scores	101007
23	Non-abundant sums	77408
24	Lexicographic permutations	86462
25	1000-digit Fibonacci number	117038
26	Reciprocal cycles	62614
27	Quadratic primes	65488
28	Number spiral diagonals	83021
29	Distinct powers	78580
30	Digit fifth powers	82518
31	Coin sums	62838
32	Pandigital products	53195
33	Digit cancelling fractions	53981
34	Digit factorials	71138
35	Circular primes	64335
36	Double-base palindromes	67686
37	Truncatable primes	55429
38	Pandigital multiples	47180
39	Integer right triangles	54781
40	Champernowne's constant	60595
41	Pandigital prime	51061
42	Coded triangle numbers	56738
43	Sub-string divisibility	44362
44	Pentagon numbers	43015
45	Triangular, pentagonal, and hexagonal	53937
46	Goldbach's other conjecture	45544
47	Distinct primes factors	43144
48	Self powers	86993
49	Prime permutations	43139
50	Consecutive prime sum	46372

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