login
This site is supported by donations to The OEIS Foundation.

 

Logo

Annual Appeal: Please make a donation to keep the OEIS running. In 2018 we replaced the server with a faster one, added 20000 new sequences, and reached 7000 citations (often saying "discovered thanks to the OEIS").
Other ways to donate

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
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) k-figurate numbers; 19 is a member of A138694. Determining whether a Mersenne prime exponent one greater than a (4, 19) k-figurate 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

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified December 16 14:52 EST 2018. Contains 318167 sequences. (Running on oeis4.)