|
|
A356405
|
|
Primes that are the sum of a set of numbers taken from 1 and 2^(2^k) for k >= 0.
|
|
1
|
|
|
2, 3, 5, 7, 17, 19, 23, 257, 263, 277, 65537, 65539, 65543, 65557, 65809, 4294967569, 4295032837, 4295033107, 340282366920938463463374607431768211729, 340282366920938463463374607431768277267, 340282366920938463463374607436063179013, 340282366920938463481821351505477763347
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
COMMENTS
|
Primes in whose binary expansion sum_i d_i 2^i, d_i = 1 only if i is in A131577.
|
|
LINKS
|
|
|
EXAMPLE
|
a(6) = 19 is a term because 19 = 1 + 2^(2^0) + 2^(2^2).
|
|
MAPLE
|
exps:= [0, seq(2^i, i=0..10)]:
S:= combinat:-powerset(exps):
select(isprime, map(proc(t) local i; add(2^i, i=t) end proc, S));
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,base
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|