Iccanobif primes
Iccanobif primes is a draft programming task. It is not yet considered ready to be promoted as a complete task, for reasons that should be found in its talk page.
Iccanobif primes are prime numbers that, when reversed, are a Fibonacci number.
- Task
- Find and display the first 10 iccanobif primes.
- Stretch
- Find and display the digit count of the next 15 iccanobif primes.
- See also
Raku
sub abbr ($_) { (.chars < 41 ?? $_ !! .substr(0,20) ~ '..' ~ .substr(*-20)) ~ " (digits: {.chars})" }
say (++$).fmt('%2d') ~ ': ' ~ .flip.&abbr for (lazy (1,1,*+*…*).hyper.grep: {.flip.is-prime})[^25];
- Output:
1: 2 (digits: 1) 2: 3 (digits: 1) 3: 5 (digits: 1) 4: 31 (digits: 2) 5: 43 (digits: 2) 6: 773 (digits: 3) 7: 7951 (digits: 4) 8: 64901 (digits: 5) 9: 52057 (digits: 5) 10: 393121 (digits: 6) 11: 56577108676171 (digits: 14) 12: 940647607443258103531 (digits: 21) 13: 5237879497657222310489731409575442761 (digits: 37) 14: 9026258083384996860449366072142307801963 (digits: 40) 15: 19900335674812302969..34431012073266446403 (digits: 80) 16: 77841137362967479985..52312097783685331923 (digits: 104) 17: 37722585901567604188..29174997072830756131 (digits: 137) 18: 75736193894876131595..50767238644714305761 (digits: 330) 19: 17890336847332837620..13175300695235035913 (digits: 406) 20: 92327163101729115305..27061468856047302507 (digits: 409) 21: 50420157810698056253..67335124247362214481 (digits: 503) 22: 30511012474739380092..69296158361330018201 (digits: 888) 23: 46818547042693694555..08664543144645856321 (digits: 1020) 24: 87101347853037819884..20128396998865227391 (digits: 1122) 25: 17451656022543765336..20100243761843652461 (digits: 1911) 26: 48989340566288399474..02930339234215909399 (digits: 1947) 27: 12746927684958209654..53436989647994940101 (digits: 2283)