OFFSET
1,1
COMMENTS
The sequence of numbers z such that both z and z+1 are in the sequence begins:
164, 650, 5187, 41474, 472394, 2654210, 10125002, 21233667, 30233090, 76236554, 169869314, 344373770, 648000002
EXAMPLE
a(1) = 10 = 2^2 * 2 + 2.
a(2) = 20 = 3^2 * 2 + 2.
a(3) = 27 = 2^3 * 3 + 3.
a(9) = 100 = 7^2 * 2 + 2.
a(11) = 164 = 9^2 * 2 + 2.
a(12) = 165 = 2^5 * 5 + 5.
CROSSREFS
KEYWORD
nonn
AUTHOR
Alex Ratushnyak, Jan 11 2015
STATUS
approved