A236684 Values of c of triples (a,b,c) of positive integers such that 1/a + 1/b + 1/c = 1/2 and a <= b <= c. Listed with multiplicity, corresponding to solutions (a,b,c) listed in lexicographic order.

42, 24, 18, 15, 12, 20, 12, 8, 10, 6

Offset

1,1

Comments

See A236681 for motivation, A236682 for a-values and A236684 for c-values.

According to J. Baez, a(1) is the Answer to the Ultimate Question of Life, the Universe, and Everything, cf. LINK.

Sequence A236681 is the range of this sequence, i.e., terms sorted in increasing order and duplicates removed.

Links

Table of n, a(n) for n=1..10.

J. Baez, 42.

Example

The solutions [a,b,c] of 1/a + 1/b + 1/c = 1/2 and a <= b <= c, listed in lexicographical order, are: {[3, 7, 42], [3, 8, 24], [3, 9, 18], [3, 10, 15], [3, 12, 12], [4, 5, 20], [4, 6, 12], [4, 8, 8], [5, 5, 10], [6, 6, 6]}.

Prog

(PARI) forvec(v=vector(3, i, [3, 42]), sum(j=1, 3, 1/v[j])==1/2&&print1(v[3]", "), 1)

Crossrefs

Cf. A236681, A236682, A236683.

Sequence in context: A334148 A033362 A033976 * A053721 A195750 A331483

Adjacent sequences: A236681 A236682 A236683 * A236685 A236686 A236687

Keyword

nonn,fini,full

Author

M. F. Hasler, Jan 29 2014

Status

approved