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 A076550 Indices of triangular numbers listed in A075088. 7
 1, 2, 3, 7, 8, 15, 32, 64, 63, 224, 255, 1280, 512, 3968, 6399, 10240, 4095, 14336, 32768, 65535, 229375, 180224, 483327, 262143, 2097151, 1048575, 14680064, 17432576, 33554432, 67108864, 16777215 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS a(32) = 134217728. - Robert G. Wilson v, Jun 28 2010 LINKS Donovan Johnson, Table of n, a(n) for n = 0..51 FORMULA A000217(a(n)) = A075088(n). MATHEMATICA f[n_] := Plus @@ Last /@ FactorInteger@n; t = Table[0, {100}]; k = 1; While[k < 10^9/4, a = f[k] + f[k + 1] -1; If[ t[[a + 1]] == 0, t[[a + 1]] = k; Print[{a, k}]]; k++ ]; t (* Robert G. Wilson v, Jun 28 2010 *) CROSSREFS Cf. A000217, A075088. Sequence in context: A097095 A101755 A363847 * A062269 A244508 A060121 Adjacent sequences: A076547 A076548 A076549 * A076551 A076552 A076553 KEYWORD nonn AUTHOR Shyam Sunder Gupta, Oct 19 2002 EXTENSIONS Edited by Ray Chandler, Dec 17 2004 a(26)-a(30) from Ray Chandler, Dec 22 2004 STATUS approved

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Last modified September 23 09:36 EDT 2023. Contains 365544 sequences. (Running on oeis4.)