A086473 - OEIS

A086473

Numbers in A058080 having only one factor pair (both distinct from 1) that add up to a sum belonging to A014092.

18, 24, 28, 50, 52, 54, 76, 92, 96, 98, 100, 112, 124, 140, 144, 148, 152, 160, 172, 176, 188, 192, 208, 212, 216, 220, 228, 232, 242, 244, 260, 266, 268, 280, 288, 290, 292, 304, 308, 316, 332, 336, 338, 344, 356, 374, 384, 388, 392, 400, 412, 434, 436, 448

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

COMMENTS

Related to the "Impossible Problem" of Martin Gardner.

REFERENCES

M. Criton, "Le Problème Impossible", Jeux Mathématiques, Tangente Hors Série No. 20 Pole Paris 2004.

LINKS

Table of n, a(n) for n=1..54.

N. Hobson, Nick's Mathematical Miscellany, Two Logicians

Dr. Rob, The Math Forum, Two Mathematicians Problem

EXAMPLE

A058080(3)=18 is in the sequence because 18=2*9=3*6 and only 2+9=11 belongs to A014092. However, A058080(7)=30 is not in the sequence because 30=2*15=3*10=5*6 with both 2+15 and 5+6 belonging to A014092.

CROSSREFS

Cf. A058080, A014092.

Sequence in context: A050772 A376507 A376540 * A271327 A243539 A076770

Adjacent sequences: A086470 A086471 A086472 * A086474 A086475 A086476

KEYWORD

nonn

AUTHOR

Lekraj Beedassy, Sep 09 2003

EXTENSIONS

Corrected and extended by Ray Chandler, Sep 21 2003

STATUS

approved