login
A126836
Ramanujan numbers (A000594) read mod 7.
3
1, 4, 0, 5, 0, 0, 0, 4, 2, 0, 1, 0, 0, 0, 0, 3, 0, 1, 0, 0, 0, 4, 4, 0, 4, 0, 0, 0, 2, 0, 0, 3, 0, 0, 0, 3, 4, 0, 0, 0, 0, 0, 2, 5, 0, 2, 0, 0, 0, 2, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 2, 1, 0, 2, 0, 0, 0, 0, 4, 0, 4, 0, 0, 0, 0, 1, 0, 4, 0, 0, 0, 6, 0, 0, 0, 0, 0, 0, 2, 6, 0, 0, 0, 0, 0
OFFSET
1,2
LINKS
R. P. Bambah, Ramanujan’s function tau(n)—A congruence property, Bull. Amer. Math. Soc. 53 (1947), 764-765.
H. P. F. Swinnerton-Dyer, On l-adic representations and congruences for coefficients of modular forms, pp. 1-55 of Modular Functions of One Variable III (Antwerp 1972), Lect. Notes Math., 350, 1973.
FORMULA
a(n) = n*sigma_3(n) mod 7. - Michel Marcus, Apr 25 2016
MATHEMATICA
Mod[RamanujanTau@ #, 7] &@ Range@ 120 (* Michael De Vlieger, Apr 25 2016 *)
CROSSREFS
Cf. this sequence (mod 7^1), A126837 (mod 7^2), A126838 (mod 7^3).
Sequence in context: A005075 A103638 A129821 * A055241 A055242 A200295
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Feb 25 2007
STATUS
approved