

A007659


Primes p such that Ramanujan number tau(p) is divisible by p.
(Formerly M0681)


11




OFFSET

1,1


COMMENTS

Primes at which cusp form Delta_12 (see A007332) is not ordinary.


REFERENCES

J. Roberts, Lure of the Integers, Math. Assoc. America, 1992, p. 275.
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).


LINKS



MATHEMATICA

(* First do *) <<NumberTheory`Ramanujan` (* then *) Select[ Prime[ Range[ 5133]], Mod[ RamanujanTau[ # ], # ] == 0 &] (* Dean Hickerson, Jan 03 2003 *)
Select[Prime[Range[400]], Divisible[RamanujanTau[#], #]&] (* The program generates the first 5 terms of the sequence. *) (* Harvey P. Dale, Jun 06 2022 *)


CROSSREFS



KEYWORD

hard,nonn,more


AUTHOR



EXTENSIONS

a(6)=7758337633 from N. Lygeros and O. Rozier, Mar 16 2010.  N. J. A. Sloane, Mar 16 2010


STATUS

approved



