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 A169980 Numerator(Bernoulli(2n)) mod denominator(Bernoulli(2n)). 4
 0, 1, 29, 1, 29, 5, 2039, 1, 463, 775, 289, 17, 2039, 1, 811, 12899, 463, 1, 1280537, 1, 11519, 1, 637, 41, 31933, 5, 1507, 775, 811, 53, 34488049, 1, 463, 62483, 29, 289, 91560011, 1, 29, 37, 182293, 77, 2346073, 1, 56003, 230759, 1333, 1, 3051091, 1, 28859, 61, 1507 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 COMMENTS From Robert G. Wilson v, Aug 27 2010: (Start) From the von Staudt-Clausen theorem, denominator(B_2n) = product of primes p such that (p-1)|2n. Values sorted: 1, 5, 17, 29, 37, 41, 49, 53, 61, 65, 77, 101, 137, 161, 169, 173, 181, 185, 221, 229, ..., . a(n)== 1 for n's: 1, 3, 7, 13, 17, 19, 21, 31, 37, 43, 47, 49, 57, 59, 61, 67, 71, 73, 79, 91, 93, 97, ..., . a(n)== 5 for n's: 5, 25, 85, 185, 235, 295, 305, 335, 355, 365, 395, 425, 505, 535, 635, 685, 695, ..., . A051229 a(n)==17 for n's: 11, 77, 87, 121, 143, 187, 407, 517, 539, 649, 671, 737, 781, 847, 869, 1067, 1111, ..., . a(n)==29 for n's: 2, 4, 34, 38, 62, 76, 94, 118, 122, 124, 142, 188, 202, 206, 214, 218, 236, 244, ..., . A051225 a(n)==37 for n's: 39, 507, 1209, 1677, 3783, 4251, 5421, 5811, 6123, 6357, 6513, 7526, 7682, 7760, 8228, ..., . a(n)==41 for n's: 23, 123, 161, 391, 437, 529, 851, 1081, 1127, 1357, 1403, 1633, 1817, 2323, 2369, 2461, ..., . a(n)==49 for n's: 55, 275, 605, 2035, 3025, 3355, 3685, 3905, 4345, 5555, 5885, 6985, 7535, 7645, 8195, ..., . a(n)==53 for n's: 29, 203, 377, 493, 841, 899, 1073, 1247, 1363, 1711, 1943, 2059, 2117, 2813, 2929, 2987, ..., . a(n)==61 for n's: 51, 867, 2193, 3009, 3417, 6477, 7089, 8007, 8313, 8517, 10047, 10149, 11577, 11679, ..., . a(n)==65 for n's: 159, 6837, 8427, 9381, 11289, 12561, 15423, 17331, 23691, 25917, 26553, 30687, 31323, ..., . a(n)==77 for n's: 41, 287, 533, 697, 1517, 1681, 1927, 2419, 2747, 2911, 3239, 3731, 3977, 4141, 4387, ..., . (End) LINKS Robert G. Wilson v, Table of n, a(n) for n = 0..50000. Index entries for sequences related to Bernoulli numbers. [From Robert G. Wilson v, Aug 27 2010] FORMULA A000367(n) mod A002445(n). [Robert G. Wilson v, Aug 27 2010] MATHEMATICA f[n_] := Block[{b = BernoulliB[2 n]}, Mod[Numerator@b, Denominator@b]]; Array[f, 53, 0] (* Robert G. Wilson v, Aug 27 2010 *) PROG (PARI) a(n) = my(b = bernfrac(2*n)); numerator(b) % denominator(b); \\ Michel Marcus, Mar 15 2015 CROSSREFS Cf. A000367, A002445, A180315. [Robert G. Wilson v, Aug 27 2010] Sequence in context: A040866 A040867 A040868 * A040869 A111881 A040833 Adjacent sequences:  A169977 A169978 A169979 * A169981 A169982 A169983 KEYWORD nonn AUTHOR Robert G. Wilson v, Aug 19 2010 STATUS approved

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Last modified January 22 00:08 EST 2022. Contains 350481 sequences. (Running on oeis4.)