A097859 a(m,0) = a(m,m) = 2; a(m,n) = sum of primes (with repetition) dividing a(m-1,n-1) and of primes (with repetition) dividing a(m-1,n).

2, 2, 2, 2, 4, 2, 2, 6, 6, 2, 2, 7, 10, 7, 2, 2, 9, 14, 14, 9, 2, 2, 8, 15, 18, 15, 8, 2, 2, 8, 14, 16, 16, 14, 8, 2, 2, 8, 15, 17, 16, 17, 15, 8, 2, 2, 8, 14, 25, 25, 25, 25, 14, 8, 2, 2, 8, 15, 19, 20, 20, 20, 19, 15, 8, 2, 2, 8, 14, 27, 28, 18, 18, 28, 27, 14, 8, 2, 2, 8, 15, 18, 20, 19

Offset

0,1

Comments

Numbers not appearing in this sequence: 1,3,5,11,12,13 and probably no others. - Robert G. Wilson v, Sep 03 2004

Links

Table of n, a(n) for n=0..83.

Example

a(6,2) = sum of primes dividing a(5,1) = 9, 3+3 and of primes dividing a(5,2) = 14, 2+7. So a(6,2) = 3 + 3 + 2 + 7 = 15.
Triangle begins:
2
2 2
2 4 2
2 6 6 2
2 7 10 7 2
2 9 14 14 9 2
2 8 15 18 15 8 2
2 8 14 16 16 14 8 2
2 8 15 17 16 17 15 8 2

Mathematica

PrimeFactors[n_] := Flatten[ Table[ #[[1]], { #[[2]]}] & /@ FactorInteger[n]]; a[m_, 0] = a[m_, m_] = 2; a[m_, n_] := a[m, n] = Plus @@ Join[ PrimeFactors[ a[m - 1, n - 1]], PrimeFactors[ a[m - 1, n]]]; Table[ a[m, n], {m, 0, 12}, {n, 0, m}] (* Robert G. Wilson v, Sep 03 2004 *)

Crossrefs

Row maxima in A098330.

Sequence in context: A353589 A237709 A250200 * A028326 A156046 A048003

Adjacent sequences: A097856 A097857 A097858 * A097860 A097861 A097862

Keyword

nonn,tabl

Author

Leroy Quet, Sep 01 2004

Extensions

More terms from Robert G. Wilson v, Sep 03 2004

Status

approved