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 A294025 Odd abundant numbers with a record small gap to the next odd abundant number. 2
 945, 5355, 5775, 6435, 8415, 34125, 1828827, 3321765909 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS The corresponding gaps are 630, 420, 210, 180, 90, 30, 18, 6. The upper ends are 1575, 5775, 5985, 6615, 8505, 34155, 1828845, 3321765915, ... Emmanuel Vantieghem has determined that for k = 76728582876430878992529528245373 the numbers k and k+2 are abundant, so the last term of this sequence is <= k. - Giovanni Resta, Nov 09 2017 LINKS Carlos Rivera, Puzzle 880. Consecutive odd abundant integers EXAMPLE Odd abundant numbers are 945, 1575, 2205, 2835, 3465, 4095, 4725, 5355, 5775, 5985, 6435, 6615, ... Their differences are 630, 630, 630, 630, 630, 630, 630, 420, 210, 450, 180, ... The records of small differences are 630, 420, 210, 180, ... And the corresponding terms are 945, 5355, 5775, 6435, ... MATHEMATICA oaQ[n_] := OddQ[n] && DivisorSigma[1, n] > 2 n; s = Select[Range[100000], oaQ]; a={}; dmin = 1000; Do[d=s[[j+1]]-s[[j]]; If[d 2*n, if (! lastoa, lastoa = n, if ((nmg = n - lastoa) < mg, mg = nmg; print1(lastoa, ", "))); lastoa = n; ); ); } \\ Michel Marcus, Nov 09 2017 CROSSREFS Cf. A005231. Sequence in context: A188263 A188342 A109729 * A275449 A293186 A294027 Adjacent sequences:  A294022 A294023 A294024 * A294026 A294027 A294028 KEYWORD nonn,fini,more AUTHOR Amiram Eldar, Oct 22 2017 EXTENSIONS a(8) from Giovanni Resta, Nov 09 2017 STATUS approved

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Last modified April 3 20:29 EDT 2020. Contains 333199 sequences. (Running on oeis4.)