A132833 Largest terms a(n) forming a self-convolution of an integer sequence (A132834) such that: a(n) <= 3*a(n-1) for n>0 with a(0)=1.

1, 2, 5, 14, 42, 126, 377, 1130, 3390, 10170, 30509, 91526, 274577, 823730, 2471190, 7413570, 22240710, 66722130, 200166390, 600499170, 1801497510, 5404492530, 16213477590, 48640432770, 145921298310, 437763894930, 1313291684789

Offset

0,2

Links

Table of n, a(n) for n=0..26.

Prog

(PARI) {a(n)=local(B=[1]); if(n==0, 1, for(k=1, n, t=3*a(k-1); B=concat(B, t); B[ #B]=t+1-denominator(Vec(Ser(B)^(1/2))[ #B]) )); B[n+1]}

Crossrefs

Cf. A132834 (square-root); A132831 (variant).

Sequence in context: A174176 A298367 A025274 * A293347 A148326 A148327

Adjacent sequences: A132830 A132831 A132832 * A132834 A132835 A132836

Keyword

nonn

Author

Paul D. Hanna, Sep 07 2007

Status

approved