A126842 Ramanujan numbers (A000594) read mod 13.

1, 2, 5, 10, 7, 10, 0, 6, 3, 1, 0, 11, 8, 0, 9, 7, 4, 6, 3, 5, 0, 0, 11, 4, 2, 3, 9, 0, 1, 5, 12, 11, 0, 8, 0, 4, 3, 6, 1, 3, 6, 0, 11, 0, 8, 9, 1, 9, 11, 4, 7, 2, 10, 5, 0, 0, 2, 2, 7, 12, 3, 11, 0, 12, 4, 0, 9, 1, 3, 0, 10, 5, 6, 6, 10, 4, 0, 2, 4, 10, 5, 12, 9, 0, 2, 9, 5, 0, 8, 3, 0, 6, 8, 2, 8, 3, 7

Offset

1,2

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

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.

Mathematica

a[n_] := Mod[RamanujanTau[n], 13]; Array[a, 100] (* Amiram Eldar, Jan 05 2025 *)

Prog

(PARI) a(n) = ramanujantau(n) % 13; \\ Amiram Eldar, Jan 05 2025

Crossrefs

Cf. A000594.

Sequence in context: A361806 A188525 A324503 * A291933 A332198 A154680

Adjacent sequences: A126839 A126840 A126841 * A126843 A126844 A126845

Keyword

nonn,changed

Author

N. J. A. Sloane, Feb 25 2007

Status

approved