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 A050367 Number of ways to factor n into 2 kinds of 2, 3 kinds of 3, ... 3
 1, 2, 3, 7, 5, 12, 7, 20, 15, 20, 11, 45, 13, 28, 30, 59, 17, 66, 19, 75, 42, 44, 23, 150, 40, 52, 64, 105, 29, 150, 31, 162, 66, 68, 70, 270, 37, 76, 78, 250, 41, 210, 43, 165, 165, 92, 47, 477, 77, 180, 102, 195, 53, 326, 110, 350, 114, 116, 59, 630, 61, 124, 231 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS N. J. A. Sloane, Table of n, a(n) for n = 1..1000 FORMULA Dirichlet g.f.: Product_{n>=2} 1/(1-1/n^s)^n. PROG (PARI, modeled on Michael Somos's program for A007896, from N. J. A. Sloane, May 26 2014) {a(n) = my(A, v, w, m); if( n<1, 0, \\ define unit vector v = [1, 0, 0, ...] of length n v = vector(n, k, k==1);    for(k=2, n,            m = #digits(n, k) - 1; \\ expand 1/(1-x)^k out far enough            A = (1 - x)^ -k + x * O(x^m); \\ w = zero vector of length n            w = vector(n); \\ convert A to a vector            for(i=0, m, w[k^i] = polcoeff(A, i)); \\ build the answer            v = dirmul(v, w)       ); v[n]   ) }; \\ produce the sequence vector(100, n, a(n)) CROSSREFS Sequence in context: A139317 A117928 A064011 * A192175 A294205 A059459 Adjacent sequences:  A050364 A050365 A050366 * A050368 A050369 A050370 KEYWORD nonn AUTHOR Christian G. Bower, Oct 15 1999 STATUS approved

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Last modified October 18 08:08 EDT 2019. Contains 328146 sequences. (Running on oeis4.)