|
Search: id:A051200
|
|
|
| A051200 |
|
Except for initial term, primes of form "n 3's followed by 1". |
|
+0
15
|
|
| 3, 31, 331, 3331, 33331, 333331, 3333331, 33333331, 333333333333333331, 3333333333333333333333333333333333333331, 33333333333333333333333333333333333333333333333331
(list; graph; listen)
|
|
|
OFFSET
|
1,1
|
|
|
COMMENT
|
"A remarkable pattern that is entirely accidental and leads nowhere" - M. Gardner, referring to the first 8 terms.
a(1)*a(2)*a(3) = 34179391, a Zeisel number (A051015) with coefficients (10,21).
a(1)*a(2)*a(3)*a(4) = 1139233281421, a Zeisel number with coefficients (10,21).
a(1)*a(2)*a(3)*a(4)*a(5) = 379741768929343351, a Zeisel number with coefficients (10,21).
a(1)*a(2)*a(3)*a(4)*a(5)*a(6) = 1265805010367017001532181, a Zeisel number with coefficients (10,21).
a(1)*a(2)*a(3)*a(4)*a(5)*a(6)*a(7) = 42193497392022209194699696424911, a Zeisel number with coefficients (10,21).
|
|
REFERENCES
|
M. Gardner, The Last Recreations, Springer, 1997, p. 194.
W. Sierpinski, 200 Zadan z Elementarnej Teorii Liczb, Warszawa, 1964; Problem 88 [in English: 200 Problems from the Elementary Theory of Numbers]
F. Smarandache, Properties of numbers, University of Craiova, 1973
|
|
LINKS
|
M. L. Perez et al., eds., Smarandache Notions Journal
Eric Weisstein's World of Mathematics, Link to a section of The World of Mathematics.
|
|
CROSSREFS
|
Cf. A055520, A089017, A089018, A093671, A056698, A105427, A105428, A033175.
Sequence in context: A011546 A152276 A136024 this_sequence A136596 A014178 A123818
Adjacent sequences: A051197 A051198 A051199 this_sequence A051201 A051202 A051203
|
|
KEYWORD
|
nonn,nice
|
|
AUTHOR
|
N. J. A. Sloane (njas(AT)research.att.com).
|
|
EXTENSIONS
|
More terms from James A. Sellers (sellersj(AT)math.psu.edu)
|
|
|
Search completed in 0.002 seconds
|
