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 A034934 Numbers n such that (3*n + 1)/2 is prime. 3
 1, 3, 7, 11, 15, 19, 27, 31, 35, 39, 47, 55, 59, 67, 71, 75, 87, 91, 99, 111, 115, 119, 127, 131, 151, 155, 159, 167, 171, 175, 179, 187, 195, 207, 211, 231, 235, 239, 255, 259, 267, 279, 287, 295, 299, 307, 311, 319, 327, 335, 339, 347, 371, 375, 379, 391 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Related to hyperperfect numbers of a certain form. The formula by J. Krizek is explained as follows: If p=(3n+1)/2 is prime, then it is an integer, and p must be of the form p=3m-1, i.e., p=A003627(k). OTOH, if p=A003627(k), then all k

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Last modified December 14 01:33 EST 2019. Contains 329978 sequences. (Running on oeis4.)