A076724 Sum {k = 1..n} tau(k) is a prime, where tau is the Ramanujan tau function (A000594).

2, 3, 39, 97, 172, 177, 200, 203, 318, 332, 345, 500, 519, 527, 651, 660, 722, 865, 870, 881, 890, 897, 1089, 1091, 1101, 1106, 1156, 1177, 1192, 1205, 1369, 1370, 1393, 1425, 1459, 1466, 1499, 1500, 1503, 1505, 1517, 1519, 1703, 1755, 1779, 1782, 1786

Offset

1,1

Links

Table of n, a(n) for n=1..47.

Mathematica

Needs["NumberTheory`Ramanujan`"]; s = 0; Do[s = s + RamanujanTau[n]; If[PrimeQ[s], Print[n]], {n, 1, 10^4}]
Flatten[Position[Accumulate[RamanujanTau[Range[0, 1800]]], _?(PrimeQ[ #]&)]]-1 (* Harvey P. Dale, Dec 22 2015 *)

Crossrefs

Cf. A000594.

Sequence in context: A039820 A331204 A153745 * A080393 A111683 A323734

Adjacent sequences: A076721 A076722 A076723 * A076725 A076726 A076727

Keyword

nonn

Author

Robert G. Wilson v, Dec 30 2002

Status

approved