A307890 Prime centuries with at least one prime year in each decade and exactly one prime year in decades 1 to 8.
3677, 4073, 16447, 118463, 211217, 357131, 368153, 582017, 932413, 1172777, 1239443, 2284027, 2421473, 3900931, 4943777, 5046053, 6850463, 6966059, 8046347, 10448783, 11548777, 12849937, 15198811, 16031237, 17315087, 19443679, 20075687, 20434811, 20462861, 20614667
Offset: 1
Examples
4073 is in the sequence, representing the prime sequence 407203, 407207, 407219, 407221, 407233, 407249, 407257, 407263, 407273, 407287, 407291, 407299, with 2 primes in decades 0 and 9, and 1 prime in decades 1 to 8. - _R. J. Mathar_, May 03 2019
Programs
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Maple
isA307890 := proc(n) local p, dec ; if not isprime(n) then false; else p := 100*(n-1) ; p := prevprime(p+10) ; for dec from 0 to 9 do if modp(floor(p/10), 10) <> dec then return false; end if; p := nextprime(p) ; end do: true ; end if; end proc: for i from 1 do p := ithprime(i) ; if isA307890(p) then printf("%d, \n", p) ; end if; end do: # R. J. Mathar, May 03 2019
Comments