This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A114905 Triangle where a(1,1) = 0; a(n,m) = number of terms in row (n-1) which, when added to m, are primes. 4
 0, 0, 1, 1, 2, 1, 3, 2, 1, 2, 3, 2, 2, 2, 2, 4, 1, 4, 1, 4, 0, 5, 3, 4, 2, 1, 2, 4, 5, 3, 4, 2, 2, 2, 2, 2, 6, 2, 6, 1, 5, 1, 1, 2, 6, 8, 4, 2, 3, 5, 4, 3, 1, 2, 3, 5, 5, 5, 4, 3, 2, 2, 4, 5, 4, 3, 5, 6, 5, 2, 2, 4, 3, 6, 5, 2, 2, 4, 8, 4, 6, 1, 6, 3, 4, 4, 6, 1, 6, 3, 4, 10, 4, 5, 4, 5, 2, 8, 2, 5, 4, 5, 2, 8, 2 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 1,5 LINKS Michael De Vlieger, Table of n, a(n) for n = 1..11476 (rows 1 <= n <= 150). EXAMPLE The third row is [1,2,1]. Adding m=3 to these terms gives [4,5,4], of which one number is prime. Therefore a[4,3]=1 in the next row, third column. Triangle starts 0 0 1 1 2 1 3 2 1 2 3 2 2 2 2 4 1 4 1 4 0 5 3 4 2 1 2 4 5 3 4 2 2 2 2 2 6 2 6 1 5 1 1 2 6 8 4 2 3 5 4 3 1 2 3 MAPLE A114905 := proc(rowmax) local a, n, m, t ; a := matrix(rowmax, rowmax) ; a[1, 1] := 0 ; for n from 2 to rowmax do for m from 1 to n do a[n, m] := 0 ; for t from 1 to n-1 do if isprime( m+a[n-1, t] ) then a[n, m] := a[n, m]+1 ; fi ; od ; od ; od ; RETURN(a) ; end: rowmax := 15 : a := A114905(rowmax) : for n from 1 to rowmax do for m from 1 to n do printf("%d, ", a[n, m]) ; od ; od ; # R. J. Mathar, Mar 13 2007 MATHEMATICA NestList[Function[w, Map[Function[k, Count[Map[k + # &, w], _?PrimeQ]], Range[Length@ w + 1]]], {0}, 13] // Flatten (* Michael De Vlieger, Sep 06 2017 *) CROSSREFS Cf. A114906, A114919, A114920. Sequence in context: A296976 A182321 A285731 * A200651 A126597 A261867 Adjacent sequences:  A114902 A114903 A114904 * A114906 A114907 A114908 KEYWORD nonn,tabl AUTHOR Leroy Quet, Jan 06 2006 EXTENSIONS Corrected and extended by R. J. Mathar, Mar 13 2007 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
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified February 16 21:59 EST 2019. Contains 320200 sequences. (Running on oeis4.)