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 A278779 Numbers n such that A000041(n) is of the form 2^2 * k for odd k. 7
 26, 30, 55, 58, 59, 62, 74, 78, 80, 84, 100, 108, 112, 113, 117, 124, 126, 135, 153, 187, 191, 200, 205, 258, 265, 280, 291, 310, 317, 323, 336, 337, 342, 344, 351, 352, 353, 358, 359, 365, 374, 380, 384, 404, 409, 416, 444, 445, 458, 481, 485, 492, 501, 503 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Numbers n such that A278478(n) = 2. Also numbers n such that A000041(n) has twice as many even divisors as odd divisors. LINKS Colin Barker, Table of n, a(n) for n = 1..1000 FORMULA A000041(a(n)) = A278196(n). PROG (PARI) isok(n) = valuation(numbpart(n), 2)==2; select(n->isok(n), vector(1000, n, n)) CROSSREFS Cf. A000041, A278196, A278780, A278781, A278782, A278783, A278784. Positions of 2's in A278478. Sequence in context: A303815 A069962 A178098 * A045163 A282110 A275192 Adjacent sequences:  A278776 A278777 A278778 * A278780 A278781 A278782 KEYWORD nonn AUTHOR Colin Barker, Nov 28 2016 STATUS approved

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Last modified September 24 11:38 EDT 2020. Contains 337318 sequences. (Running on oeis4.)