The OEIS is supported by the many generous donors to the OEIS Foundation.

 Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 59th year, we have over 358,000 sequences, and we’ve crossed 10,300 citations (which often say “discovered thanks to the OEIS”). Other ways to Give
 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A114920 Triangle where a(0,0) = 1; a(n,m) = number of terms in row (n-1) which, when added to m, are primes. 4
 1, 0, 1, 0, 1, 2, 1, 2, 2, 2, 3, 4, 1, 3, 1, 2, 3, 4, 1, 4, 0, 2, 4, 3, 4, 2, 2, 1, 4, 6, 2, 5, 2, 3, 1, 2, 5, 6, 3, 4, 2, 4, 2, 2, 2, 6, 7, 2, 6, 1, 5, 1, 3, 2, 6, 5, 7, 4, 2, 4, 5, 4, 3, 2, 2, 4, 7, 7, 3, 7, 2, 3, 3, 4, 3, 7, 2, 3, 11, 3, 5, 3, 9, 2, 4, 1, 5, 3, 9, 2, 4, 8, 5, 9, 4, 6, 2, 4, 2, 8, 4, 6, 2, 4, 2 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 0,6 LINKS Michael De Vlieger, Table of n, a(n) for n = 0..11627 (rows 0 <= n <= 150). EXAMPLE Row 3 of the triangle is [1,2,2,2]. Adding 0 to these gives [1,2,2,2], of which 3 terms are primes. Adding 1 to these gives [2,3,3,3], of which 4 terms are primes. Adding 2 to these gives [3,4,4,4], of which one term is prime. Adding 3 to these gives [4,5,5,5], of which 3 terms are primes. Adding 4 to these gives [5,6,6,6], of which one term is prime. So row 4 is [3,4,1,3,1]. Triangle begins: 1; 0, 1; 0, 1, 2; 1, 2, 2, 2; 3, 4, 1, 3, 1; 2, 3, 4, 1, 4, 0; 2, 4, 3, 4, 2, 2, 1; ... MATHEMATICA NestList[Function[w, Map[Function[k, Count[Map[k + # &, w], _?PrimeQ]], Range[0, Length@ w]]], {1}, 13] // Flatten (* Michael De Vlieger, Sep 07 2017 *) PROG (PARI) {v=[1]; for(k=1, 20, w=vector(length(v)+1); for(i=0, length(v), for(j=1, length(v), if(isprime(v[j]+i), w[i+1]++))); v=w; print(v))} \\ Lambert Herrgesell(zero815(AT)googlemail.com), Jan 13 2006 CROSSREFS Cf. A114919, A114905, A114906. Sequence in context: A123505 A320779 A356876 * A283190 A030361 A060715 Adjacent sequences: A114917 A114918 A114919 * A114921 A114922 A114923 KEYWORD nonn,tabl AUTHOR Leroy Quet, Jan 07 2006 EXTENSIONS More terms from Lambert Herrgesell (zero815(AT)googlemail.com), Jan 13 2006 STATUS approved

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

Last modified December 7 08:24 EST 2022. Contains 358649 sequences. (Running on oeis4.)