OFFSET
1,2
REFERENCES
Jeffrey Shallit, personal communication.
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
LINKS
Chai Wah Wu, Table of n, a(n) for n = 1..10000 (terms 1..1000 from Sean A. Irvine)
Thomas Bloom, Problem 9, Erdős Problems.
Roger Crocker, On the sum of a prime and of two powers of two, Pacific J. Math. 36(1): 103-107 (1971).
Hao Pan, On the integers not of the form {$p+2^a+2^b$},, arXiv:0905.3809 [math.NT], 2009.
Terence Tao, Erdős problem database, see entry no. 9.
PROG
(Python)
from itertools import count, islice, combinations
from sympy import isprime
def A006286_gen(startvalue=1): # generator of terms >= startvalue
for i in count(max(startvalue, 1)):
l = i.bit_length()
for j in range(1, l):
if isprime(i-(1<<j)):
break
else:
for p in combinations(range(l), 2):
if isprime(i-(1<<p[0])-(1<<p[1])):
break
else:
yield i
CROSSREFS
KEYWORD
nonn
AUTHOR
EXTENSIONS
More terms from Sean A. Irvine, Feb 22 2017
STATUS
approved