

A125772


Primes not of the form j*T_k +/ 1, where T_k is the kth triangular number greater than 9.


0



2, 3, 5, 7, 13, 17, 23, 47, 53, 97, 103, 163, 173, 193, 227, 257, 283, 317, 347, 353, 367, 373, 383, 443, 457, 487, 523, 557, 563, 607, 653, 677, 733, 743, 773, 787, 823, 853, 877, 887, 907, 977, 983, 997, 1033, 1097, 1163, 1193, 1213, 1237, 1277, 1283, 1307
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OFFSET

1,1


COMMENTS

Since all primes would eventually appear in A125765 or A125766 because (p +/1) times 1(1+1)/2 equals (p +/ 1) let us not use the first triangular number 1.


LINKS



EXAMPLE

17 is not of the form j*T_k +/ 1 for any j = 1 or 2 and the triangular numbers, 10, 15 or 21.


MATHEMATICA

s = {}; Do[m = j*k*(k + 1)/2; If[PrimeQ[m  1], AppendTo[s, m  1]]; If[PrimeQ[m + 1], AppendTo[s, m + 1]], {j, 140}, {k, 4, 43}]; Complement[ Prime@ Range@220, Take[Union@s, 200]]


CROSSREFS



KEYWORD

nonn


AUTHOR



STATUS

approved



