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- #!/usr/bin/ruby
- # a(n) is the maximum prime factor of the concatenation of a(n-2) and a(n-1), with a(1)=1 and a(2)=2
- # https://oeis.org/A280894
- include('../../../factordb/auto.sf')
- func a(n) is cached {
- return 1 if (n == 1)
- return 2 if (n == 2)
- gpf(Num(join('', a(n-2), a(n-1))))
- }
- var fh = File('bfile.txt').open_w
- fh.autoflush(true)
- for n in (1..10000) {
- var row = "#{n} #{a(n)}"
- say row
- fh.say(row)
- }
- __END__
- not FF: 6520842354140118040355763693879924323002857350048725428113176051404264796719454440763187888611339210218453742791930047642196926300803432024917606770110282689443102347792520396533935876342678176379567979056549996383541341367
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