A249388 - OEIS

A249388

Put a [+] b = A(A(a) + A(b)), where A=A007913. The sequence lists consecutive row "sums" of triangle A248473, using [+].

1, 2, 1, 2, 3, 2, 2, 94, 1, 1, 1, 2, 6, 2, 17, 2, 2, 1187, 6, 2, 1, 62, 2, 56883, 14, 3, 14471, 2, 14, 3018, 34, 6, 3, 29, 67, 19, 1, 38, 528846, 9758, 14, 18278015, 163506530, 767014, 7, 2, 2611563, 2081053770, 3, 2, 2, 53654, 94, 17175330570, 2, 1612685866

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OFFSET

0,2

LINKS

Table of n, a(n) for n=0..55.

MATHEMATICA

a7913[n_]:=a7913[n]=Times@@(#[[1]]^Mod[#[[2]], 2])&[Transpose[FactorInteger[n]]];

ab[x_, y_]:=ab[x, y]=a7913[a7913[x]+a7913[y]];

Map[Fold[ab, First[#], Rest[#]]&, Table[a7913[Binomial[a7913[m], a7913[k]]], {m, 0, 50}, {k, 0, m}]] (* Peter J. C. Moses, Oct 27 2014 *)

CROSSREFS

Cf. A007913, A248470, A248473.

Sequence in context: A275438 A275440 A147784 * A051329 A291711 A173964

Adjacent sequences: A249385 A249386 A249387 * A249389 A249390 A249391

KEYWORD

nonn

AUTHOR

Vladimir Shevelev and Peter J. C. Moses, Oct 27 2014

STATUS

approved