A265913 Values of Ramanujan's tau function that are prime.

-80561663527802406257321747, -11695495424911987900947041440697, -261735233712444492786795215139587, -686681472061569603985711525865543, -8467957012200178807169459266490129, -205501290141049152491380112020976837, 4705942878159923138262416607648599521

Offset

1,1

Comments

Here, negative integers whose absolute value is prime are considered prime.

Links

Dana Jacobsen, Table of n, a(n) for n = 1..1000 (first 23 terms from Eric W. Weisstein)

Eric Weisstein's World of Mathematics, Tau Function Prime.

Formula

a(n) = A000594(A135430(n)).

Example

A135430(1) = 63001, and tau(63001) = -80561663527802406257321747, so a(1) = -80561663527802406257321747.

Prog

(PARI) for (x=0, 1000, n=(2*x+1)^2; a=ramanujantau(n); if(isprime(abs(a)), print1(a", "))) \\ Dana Jacobsen, Dec 30 2015
(Perl) use ntheory ":all"; for (0..1000) { my $n = (2*$_+1)**2; my $a = ramanujan_tau($n); say $a if is_prime(abs($a)); } # Dana Jacobsen, Dec 30 2015

Crossrefs

Cf. A135430 (values of n for which tau(n) is prime).

Cf. A000594 (Ramanujan's tau function tau(n)).

Sequence in context: A338953 A345296 A272520 * A217425 A214266 A175274

Adjacent sequences: A265910 A265911 A265912 * A265914 A265915 A265916

Keyword

sign

Author

Eric W. Weisstein, Dec 18 2015

Status

approved