# [seqfan] Re: Sums of a Mersenne prime and a Fermat prime; Means of a Mersenne prime and a Fermat prime; prime means of a Mersenne prime and a Fermat prime

Richard Mathar mathar at strw.leidenuniv.nl
Sat Mar 6 20:57:07 CET 2010

```In the list of A019434(i) + A000668(j) in
http://list.seqfan.eu/pipermail/seqfan/2010-March/003859.html
the numbers 34 is missing and and 36 ought be 38 :

6, 8, 10, 12, 20, 24, 34, 36, 48, 130, 132, 144, 260, 264, 288, 384, 8194,
8196, 8208, 8448, 65540, 65544, 65568, 65664, 73728, 131074, 131076,
131088, 131328, 196608, 524290, 524292, 524304, 524544, 589824, 2147483650,
2147483652, 2147483664, 2147483904, 2147549184, 2305843009213693954,
2305843009213693956, 2305843009213693968, 2305843009213694208,
2305843009213759488, 618970019642690137449562114,
618970019642690137449562116, 618970019642690137449562128,
618970019642690137449562368, 618970019642690137449627648,
162259276829213363391578010288130, 162259276829213363391578010288132,

Half of these:

3, 4, 5, 6, 10, 12, 17, 18, 24, 65, 66, 72, 130, 132, 144, 192, 4097, 4098,
4104, 4224, 32770, 32772, 32784, 32832, 36864, 65537, 65538, 65544, 65664,
98304, 262145, 262146, 262152, 262272, 294912, 1073741825, 1073741826,
1073741832, 1073741952, 1073774592, 1152921504606846977,
1152921504606846978, 1152921504606846984, 1152921504606847104,
1152921504606879744, 309485009821345068724781057,
309485009821345068724781058, 309485009821345068724781064,
309485009821345068724781184, 309485009821345068724813824,

Primes in these halved: 3,5,17,65537,..

```