A143837 a(n) = A066839(A141037(n)).

1, 3, 4, 6, 7, 10, 11, 16, 21, 24, 26, 39, 45, 52, 66, 73, 93, 99, 102, 105, 110, 111, 118, 153, 180, 194, 240, 251, 301, 331, 435, 479, 487, 504, 513, 518, 525, 546, 748, 753, 921, 993, 1202, 1285, 1352, 1600, 1716, 1869, 1902, 2221, 2477, 2601, 2640, 2807

Offset

1,2

Links

Amiram Eldar, Table of n, a(n) for n = 1..250

Formula

a(n) = A066839(A141037(n)).

Example

The value of 16 in this sequence corresponds to 1+2+3+4+6 = 16 with 1, 2, 3, 4 and 6 being the divisors of 36 <= sqrt(36).

Maple

A066839 := proc(n) a := 0 ; for k in numtheory[divisors](n) do if k^2 <= n then a := a+k ; fi; od: a ; end: A143837 := proc() rec := -1; for n from 1 do r := A066839(n) ; if r > rec then printf("%d, ", r) ; rec := r; fi; od: end: A143837() ; # R. J. Mathar, Nov 03 2008

Prog

(PARI) lista(nn) = {my(ms = 0); for (n=1, nn, sqn = sqrt(n); s = sumdiv(n, d, d*(d<=sqn)); if (s > ms, print1(s, ", "); ms = s); ); } \\ Michel Marcus, Oct 05 2015

Crossrefs

Cf. A066839, A141037.

Sequence in context: A065135 A229792 A101299 * A354005 A330172 A206903

Adjacent sequences: A143834 A143835 A143836 * A143838 A143839 A143840

Keyword

nonn

Author

J. Lowell, Sep 02 2008

Extensions

More terms from R. J. Mathar, Nov 03 2008

Name edited by Jon E. Schoenfield at the suggestion of Joerg Arndt, Oct 12 2015

Status

approved