Voozh

A132837

Largest terms a(n) forming a self-convolution 4th power of an integer sequence (A132838) such that: a(n) <= 4*a(n-1) for n>0 with a(0)=1.

1, 4, 14, 56, 221, 884, 3534, 14136, 56542, 226168, 904672, 3618688, 14474751, 57899004, 231596014, 926384056, 3705536222, 14822144888, 59288579552, 237154318208, 948617272832, 3794469091328, 15177876365312, 60711505461248

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,2

LINKS

Table of n, a(n) for n=0..23.

PROG

(PARI) {a(n)=local(A, t, r=1); A=if(n==0, [1], vector(n, j, a(j-1))); if(n==0, r=1, t=a(n-1); if(denominator(Vec(Ser(concat(A, 4*t))^(1/4))[n+1])==1, r=4*t, if(denominator(Vec(Ser(concat(A, 4*t-1))^(1/4))[n+1])==1, r=4*t-1, if(denominator(Vec(Ser(concat(A, 4*t-2))^(1/4))[n+1])==1, r=4*t-2, r=4*t-3)))); r}

CROSSREFS

Cf. A132838 (fourth-root); variants: A132831, A132835, A132839.

Sequence in context: A143406 A329777 A323787 * A259808 A149491 A073155

Adjacent sequences: A132834 A132835 A132836 * A132838 A132839 A132840

KEYWORD

nonn

AUTHOR

Paul D. Hanna, Sep 10 2007

STATUS

approved

URL: https://oeis.org/A132837

⇱ A132837 - OEIS