

A178382


Primes that are in classes k+ and k for some k in the ErdősSelfridge classification of primes.


0



2, 3, 5, 7, 17, 29, 41, 43, 61, 79, 101, 131, 137, 149, 173, 197, 211, 223, 227, 229, 233, 239, 241, 251, 271, 281, 293, 307, 311, 331, 353, 397, 439, 449, 463, 523, 569, 593, 607, 641, 683, 691, 727, 733, 751, 761, 787, 821, 853, 859, 919, 947, 953, 983, 1031
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OFFSET

1,1


COMMENTS

The first five terms are the only primes in both class 1+ and class 1. The Mathematica program assigns 2 and 3 to class 0 in order to simplify the algorithm; they are actually in classes 1 and 1+.


LINKS



FORMULA



MATHEMATICA

classp[2]=0; classp[3]=0; SetAttributes[classp, Listable]; classp[p_] := classp[p] = 1+Max@@classp[First/@FactorInteger[p+1]]; classm[2]=0; classm[3]=0; SetAttributes[classm, Listable]; classm[p_] := classm[p] = 1+Max@@classm[First/@FactorInteger[p1]]; Select[Prime[Range[1000]], classp[ # ]==classm[ # ]&]


CROSSREFS



KEYWORD

nonn


AUTHOR



STATUS

approved



