

A090481


Primes p such that tau(p1)+tau(p+1) is larger than for any previous term. (Smallest prime sandwiched between more composite numbers.)


7



2, 3, 5, 7, 11, 17, 19, 29, 41, 71, 179, 181, 239, 419, 701, 839, 881, 1259, 1871, 2161, 2521, 4159, 5039, 7561, 10079, 13441, 13859, 20161, 22679, 30241, 35281, 45361, 55439, 65519, 110879, 138599, 151201, 166319, 226799, 262079, 327599, 332641
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,1


LINKS

Donovan Johnson, Table of n, a(n) for n = 1..100


EXAMPLE

17 follows 11 and 13 is not a term as tau(10) + tau(12) = tau(12) + tau(14) = 10.


MATHEMATICA

a = {}; t = 0; Do[p = Prime[n]; s = DivisorSigma[0, p  1] + DivisorSigma[0, p + 1]; If[s > t, t = s; AppendTo[a, p]], {n, 1, 10^5}]; a (* Robert G. Wilson v, Dec 04 2003 *)


CROSSREFS

Cf. A090482, A000005.
Sequence in context: A228424 A335325 A189828 * A094342 A164641 A058982
Adjacent sequences: A090478 A090479 A090480 * A090482 A090483 A090484


KEYWORD

nonn


AUTHOR

Amarnath Murthy, Dec 02 2003


EXTENSIONS

More terms from Robert G. Wilson v, Dec 04 2003


STATUS

approved



