A378735 Greatest non-abundant divisor of the n-th abundant number.

6, 9, 10, 8, 15, 9, 10, 21, 16, 27, 28, 15, 33, 35, 9, 39, 16, 28, 44, 45, 32, 50, 51, 52, 27, 28, 57, 15, 63, 44, 69, 35, 16, 75, 52, 32, 81, 28, 87, 44, 45, 93, 64, 98, 99, 50, 68, 52, 105, 27, 110, 111, 32, 76, 117, 16, 123, 63, 129, 130, 44, 135, 136, 92, 35, 141, 32, 147, 75, 152, 153, 154, 52, 159, 64, 81, 165

Offset

1,1

Links

Antti Karttunen, Table of n, a(n) for n = 1..20000

Formula

a(n) = A378665(A005101(n)).

a(n) >= A378736(n).

Prog

(PARI)
A294935(n) = (sigma(n)<=(2*n));
A378665(n) = { fordiv(n, d, if(A294935(n/d), return(n/d))); (1); };
k=0; n=0; while(k<105, n++; if(!A294935(n), k++; print1(A378665(n), ", ")));

Crossrefs

Cf. A005101, A294935, A378665.

Cf. also A378736 and the points of differences A378737.

Sequence in context: A332439 A070598 A378736 * A262435 A124257 A066385

Adjacent sequences: A378732 A378733 A378734 * A378736 A378737 A378738

Keyword

nonn,new

Author

Antti Karttunen, Dec 06 2024

Status

approved