cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A174885 Prime hypotenuses c with concatenation p = c//a//b a prime number.

Original entry on oeis.org

29, 409, 461, 661, 929, 1249, 1289, 1381, 1801, 1901, 2081, 2609, 2621, 2749, 3041, 3301, 3881, 5309, 5701, 6421, 6481, 6521, 6529, 7349, 7489, 7789, 8641, 8849, 9349, 9629, 9649, 9689, 9829, 10321, 10709, 10861, 12841, 14321, 14561, 15061, 16661
Offset: 1

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Author

Ulrich Krug (leuchtfeuer37(AT)gmx.de), Apr 01 2010

Keywords

Comments

See comments in A174825
c is the prime hypotenuse c, i. e. c of a primitive Pythagorean triple: a^2 + b^2 = c^2

Examples

			p = c//a//b: 292021, 409120391, 461380261, 661300589, 929920129, 1249960799, 12895601161,
13811020931, 18011680649, 19011820549, 208116401281, 260918801809, 262111002379,
27492580949, 30414403009, 330129401501, 388123603081, 53095300309, 570122205251
29^2=20^2+21^2, 409^2=120^2+391^2, 461^2=380^2+261^2,
661^2=300^2+589^2, 929^2=920^2+129^2, 1249^2=960^2+799^2,
1289^2=560^2+1161^2,1381^2=1020^2+931^2, 1801^2=1680^2+649^2,
1901^2=1820^2+549^2, 2081^2=1640^2+1281^2, 2609^2=1880^2+1809^2,
2621^2=1100^2+2379^2, 2749^2=2580^2+949^2, 3041^2=440^2+3009^2,
3301^2=2940^2+1501^2, 3881^2=2360^2+3081^2, 5309^2=5300^2+309^2,
5701^2=2220^2+5251^2
		

References

  • W. W. R. Ball, H. S. M. Coxeter: Mathematical Recreations and Essays, New York: Dover, 1987
  • L. E. Dickson: "Rational Right Triangles", ch. 4 in History of the Theory of numbers, vol. II, Dover Publications 2005
  • W. Sierpinski: Pythagorean Triangles, Mineola, NY, Dover Publications, Inc, 2003

Crossrefs

Extensions

More terms from Zak Seidov, Apr 04 2010