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 A344978 Numbers k such that A011772(k) is equal to A344878(k), but k is not a power of prime. 3
 21, 26, 39, 50, 57, 74, 75, 78, 93, 98, 111, 122, 129, 146, 147, 150, 183, 194, 201, 205, 218, 219, 222, 237, 242, 291, 294, 301, 305, 309, 314, 327, 338, 362, 363, 366, 381, 386, 405, 417, 438, 452, 453, 458, 471, 482, 489, 505, 507, 543, 554, 578, 579, 582, 597, 605, 610, 626, 633, 654, 657, 669, 674, 676, 687 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Numbers k for which A344976(k) = 0, and A001221(k) > 1. LINKS FORMULA For all n, A344970(a(n)) = 1. PROG (PARI) A011772(n) = { if(n==1, return(1)); my(f=factor(if(n%2, n, 2*n)), step=vecmax(vector(#f~, i, f[i, 1]^f[i, 2]))); forstep(m=step, 2*n, step, if(m*(m-1)/2%n==0, return(m-1)); if(m*(m+1)/2%n==0, return(m))); }; \\ From A011772 A344878(n) = if(1==n, n, my(f=factor(n)~); lcm(vector(#f, i, (f[1, i]^(f[2, i]+(2==f[1, i]))-1)))); isA344978(n) = (omega(n)>1&&(A344878(n)==A011772(n))); CROSSREFS Cf. A000961, A001221, A011772, A344878, A344970, A344976. Subsequence of A344975. Intersection of A024619 and A344979. Sequence in context: A347394 A035700 A134935 * A299594 A318544 A173836 Adjacent sequences:  A344975 A344976 A344977 * A344979 A344980 A344981 KEYWORD nonn AUTHOR Antti Karttunen, Jun 04 2021 STATUS approved

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Last modified July 4 11:25 EDT 2022. Contains 355075 sequences. (Running on oeis4.)