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A088949 Composite numbers k such that (A006530(k) + A020639(k))/2 is an integer that divides k; special terms of A088948. 2
4, 8, 9, 16, 25, 27, 32, 49, 64, 81, 105, 121, 125, 128, 169, 231, 243, 256, 289, 315, 343, 361, 512, 525, 529, 625, 627, 693, 729, 735, 841, 897, 935, 945, 961, 1024, 1155, 1331, 1369, 1575, 1581, 1617, 1681, 1729, 1849, 1881, 2048, 2079, 2187, 2197, 2205, 2209 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..52.

EXAMPLE

k = 315 = 3*3*5*7 (composite); (3 + 7)/2 = 5, which divides k.

PROG

(PARI) lista(nn) = {forcomposite(n=1, nn, my(f = factor(n)[, 1], x = (vecmin(f) + vecmax(f))/2); if ((denominator(x)==1) && !(n % x), print1(n, ", ")); ); } \\ Michel Marcus, Jul 09 2018

CROSSREFS

Cf. A006530, A020639, A088948, A088595, A046687.

Sequence in context: A080062 A249125 A306531 * A134600 A134601 A227476

Adjacent sequences:  A088946 A088947 A088948 * A088950 A088951 A088952

KEYWORD

nonn

AUTHOR

Labos Elemer, Nov 20 2003

EXTENSIONS

Edited by Jon E. Schoenfield, Jul 08 2018

More terms from Michel Marcus, Jul 09 2018

STATUS

approved

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Last modified October 18 10:34 EDT 2019. Contains 328147 sequences. (Running on oeis4.)