

A230400


Numbers n such that n = abc = 2(ab+ac+bc) for some positive integers a,b,c.


1




OFFSET

1,1


COMMENTS

Otherwise said: Volumes of integersided cubes equal to their surface area (assuming dimensionless unit of length).
The sequence is a finite subsequence of A055744, A069167, A073539, A090779 and A137845.


LINKS

Table of n, a(n) for n=1..10.
"Mathematically possible", Volume = Surface Area?, on facebook.com.


EXAMPLE

The triples (a,b,c) ordered by largest member(s) are (6,6,6), (8,8,4), (10,5,5), (12,6,4), (12,12,3), (15,10,3), (18,9,3), (20,5,4), (24,8,3), (42,7,3).


PROG

(PARI) L=[]; for(a=1, 99, for(b=1, a, for(c=1, b, a*b*c==2*(a*b+b*c+a*c)&&!printf("(%d, %d, %d), ", a, b, c)&&L=concat(L, a*b*c)))); vecsort(L)


CROSSREFS

Cf. A229941.
Sequence in context: A176766 A018863 A003998 * A001239 A184088 A205191
Adjacent sequences: A230397 A230398 A230399 * A230401 A230402 A230403


KEYWORD

nonn,fini,full


AUTHOR

M. F. Hasler, Oct 18 2013


STATUS

approved



