

A144326


Prime numbers that cannot be Mersenne prime exponents, by conjecture of A144325.


1



67, 191, 197, 211, 277, 331, 379, 397, 401, 541, 617, 631, 677, 727, 743, 751, 821, 937, 947, 971, 991, 1129, 1163, 1171, 1217, 1277, 1289, 1327, 1381, 1409, 1427, 1471, 1549, 1559, 1597, 1601, 1607, 1783, 1801, 1831, 1871, 1901, 2011, 2017, 2081, 2111
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,1


COMMENTS

Obviously true for the initial terms!
Conjecture: 191, 1217, 1559 and 1901 are not in fact members of this sequence, noting that they are (4, 19) kfigurate numbers; 19 is a member of A138694. Determining whether a Mersenne prime exponent one greater than a (4, 19) kfigurate number exists is sufficient to determine whether these primes are members.


LINKS

Table of n, a(n) for n=1..46.


CROSSREFS

Cf. A000040, A000043, A000668, A144313, A144315, A144325, A138694
Sequence in context: A142544 A259888 A142671 * A119593 A142891 A142049
Adjacent sequences: A144323 A144324 A144325 * A144327 A144328 A144329


KEYWORD

easy,nonn


AUTHOR

Reikku Kulon, Sep 17 2008


STATUS

approved



