This site is supported by donations to The OEIS Foundation.

 Annual appeal: Please make a donation to keep the OEIS running! Over 6000 articles have referenced us, often saying "we discovered this result with the help of the OEIS". Other ways to donate

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A036261 Triangle of numbers arising from Gilbreath's conjecture: successive absolute differences of primes (read by antidiagonals upwards, omitting the initial row of primes). 7
 1, 1, 2, 1, 0, 2, 1, 2, 2, 4, 1, 2, 0, 2, 2, 1, 2, 0, 0, 2, 4, 1, 2, 0, 0, 0, 2, 2, 1, 2, 0, 0, 0, 0, 2, 4, 1, 2, 0, 0, 0, 0, 0, 2, 6, 1, 0, 2, 2, 2, 2, 2, 2, 4, 2, 1, 0, 0, 2, 0, 2, 0, 2, 0, 4, 6, 1, 0, 0, 0, 2, 2, 0, 0, 2, 2, 2, 4, 1, 0, 0, 0, 0, 2, 0, 0, 0, 2, 0, 2, 2, 1, 0, 0, 0, 0, 0, 2, 2, 2, 2, 0, 0, 2, 4 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 REFERENCES R. K. Guy, Unsolved Problems Number Theory, A10. C. A. Pickover, The Math Book, Sterling, NY, 2009; see p. 410. LINKS T. D. Noe, Rows n=1..100 of triangle, flattened A. M. Odlyzko, Iterated absolute values of differences of consecutive primes, Math. Comp. 61 (1993), 373-380. EXAMPLE Table begins (conjecture is leading term is always 1):   2 3 5 7 11 13 17 19 23 ...   1 2 2 4  2  4  2  4 ...   1 0 2 2  2  2  2 ...   1 2 0 0  0, 0 ...   1 2 0 0  0 ...   1 2 0 0 ...   ... MATHEMATICA max = 15; triangle = Rest[ NestList[ Abs[ Differences[#] ]& , Prime[ Range[max] ], max] ]; Flatten[ Table[ triangle[[n-k+1, k]], {n, 1, max-1}, {k, 1, n}]] (* Jean-François Alcover, Jan 23 2012 *) CROSSREFS See A036262, which is the main entry for this array. Sequence in context: A035443 A180430 A246369 * A140575 A091917 A025657 Adjacent sequences:  A036258 A036259 A036260 * A036262 A036263 A036264 KEYWORD tabl,easy,nice,nonn AUTHOR EXTENSIONS More terms from Naohiro Nomoto, May 22 2001 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.