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%I #9 Jan 05 2025 01:11:05
%S 1,505,252,115,69,300,184,369,92,460,322,414,459,345,460,22,161,437,
%T 483,0,345,207,254,413,162,93,116,0,344,69,229,230,207,368,0,0,207,46,
%U 346,69,160,184,138,0,0,252,459,254,139,344,368,414,253,390,0,184,46,208,71,0
%N Ramanujan numbers (A000594) read mod 23^2.
%H Amiram Eldar, <a href="/A126846/b126846.txt">Table of n, a(n) for n = 1..10000</a>
%H Jean-Pierre Serre, <a href="http://www.numdam.org/item/?id=SDPP_1967-1968__9_1_A13_0">Une interprétation des congruences relatives à la fonction tau de Ramanujan</a>, Séminaire Delange-Pisot-Poitou, Théorie des nombres, Vol. 9, No. 1 (1967-1968), Talk no. 14, 17 p., section 4.5, page 14-11.
%H H. P. F. Swinnerton-Dyer, <a href="http://dx.doi.org/10.1007/978-3-540-37802-0_1">On l-adic representations and congruences for coefficients of modular forms</a>, pp. 1-55 of Modular Functions of One Variable III (Antwerp 1972), Lect. Notes Math., 350, 1973.
%F a(p) == sigma_11(p) (mod 23^2) for prime p of the form u^2 + 23*v^2, u >= 1 (Serre, 1968). - _Amiram Eldar_, Jan 05 2025
%t a[n_] := Mod[RamanujanTau[n], 529]; Array[a, 100] (* _Amiram Eldar_, Jan 05 2025 *)
%o (PARI) a(n) = ramanujantau(n) % 529; \\ _Amiram Eldar_, Jan 05 2025
%Y Cf. A000594, A013959.
%K nonn,changed
%O 1,2
%A _N. J. A. Sloane_, Feb 25 2007