login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A128148
a(n) = least k such that 3^k mod k = 2^n.
2
2, 2929, 41459, 2352527, 144937, 1055, 1829903, 7316185805, 114491, 3146746271, 5028467, 20299, 69609309001, 129433, 15307006153, 2149705, 66469, 559182815, 18429503, 4529951, 7094711, 83591212702535, 1251548749, 38088889
OFFSET
0,1
FORMULA
a(n) = A078457(2^n).
EXAMPLE
a(1) = A128149(3) = 2929.
a(2) = A128150(3) = 41459.
CROSSREFS
Cf. A078457 = least k such that the remainder when 3^k is divided by k is n.
Sequence in context: A353126 A242109 A078457 * A308575 A158348 A158904
KEYWORD
hard,nonn
AUTHOR
Alexander Adamchuk, Feb 16 2007
EXTENSIONS
a(7)-a(9) from A078457. Max Alekseyev, Mar 11 2009
Extended by Max Alekseyev, Mar 15 2009
a(20) from Hagen von Eitzen, Aug 01 2009
a(21)-a(23) from Max Alekseyev, Feb 13 2012
STATUS
approved