

A357670


Sliding numbers which are products of three distinct primes.


0



70, 110, 290, 1001, 1010, 1258, 3157, 3445, 5002, 6266, 6410, 50002, 1958245, 2000005, 9766649, 9775865, 20000005, 48830173, 200000005, 488283298, 2000000005, 2441410346, 6103679465, 10000000001, 12207039442, 30517905805, 50000000002, 61035172634, 152588545985, 200000000005, 305175814018
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,1


COMMENTS

A squarefree subsequence of numbers of the form p + q where 1/p + 1/q = (p + q)/10^k for some k >= 1.


LINKS



EXAMPLE

70 = 2*5*7 (70 = 20 + 50 and 1/20 + 1/50 = 0.070).
1001 = 7*11*13 (1001 = 1 + 1000 and 1/1 + 1/1000 = 1.001).
9766649 = 29*61*5521 (9766649 = 1024 + 9765625 and 1/1024 + 1/9765625 = 0.0009766649).
200000005 = 5*53*754717 (200000005 = 5 + 200000000 and 1/5 + 1/200000000 = 0.200000005).


CROSSREFS



KEYWORD

nonn,base


AUTHOR



EXTENSIONS



STATUS

approved



