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 A269525 a(1) = 1, a(n) is the sum of m < n for which a(m) has at most as many divisors as n. 1
 1, 1, 3, 6, 6, 15, 6, 28, 6, 37, 16, 66, 16, 47, 61, 100, 45, 125, 45, 162, 94, 115, 45, 240, 45, 137, 163, 306, 98, 347, 128, 365, 252, 252, 252, 456, 128, 252, 252, 477, 128, 558, 128, 437, 481, 341, 128, 819, 128, 572, 387, 623, 128, 988 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 LINKS Peter Kagey, Table of n, a(n) for n = 1..1000 EXAMPLE a(1) = 1; a(2) = 1 because a(1) has at most as many divisors as 2; a(3) = 3 because a(1) and a(2) have at most as many divisors as 3; a(4) = 6 because a(1), a(2), and a(3) have at most as many divisors as 4; a(5) = 6 because a(1), a(2), and a(3) have at most as many divisors as 5. MATHEMATICA a = {1}; Do[d = DivisorSigma[0, n]; AppendTo[a, Total@ Select[Range[n - 1], DivisorSigma[0, a[[#]]] <= d &]], {n, 2, 54}]; a (* Michael De Vlieger, Mar 24 2016 *) PROG (Java) int[] terms = new int; terms = 1; for (int i = 1; i < 100; i++) {     int count = 0;     for (int j = 0; j < i; j++) {         if (divisors(terms[j]) <= divisors(i+1)) {             count = count + j + 1;         }     }     terms[i] = count; } (PARI) lista(nn) = {va = vector(nn); print1(va = 1, ", "); for (n=2, nn, va[n] = sum(k=1, n-1, k*(numdiv(va[k]) <= numdiv(n))); print1(va[n], ", "); ); } \\ Michel Marcus, Feb 29 2016 CROSSREFS Sequence in context: A119306 A107972 A238775 * A036252 A103463 A265026 Adjacent sequences:  A269522 A269523 A269524 * A269526 A269527 A269528 KEYWORD easy,nonn AUTHOR Alec Jones, Feb 29 2016 STATUS approved

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Last modified November 17 16:03 EST 2019. Contains 329238 sequences. (Running on oeis4.)