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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. 3
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
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
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Sep 10 2007
STATUS
approved

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Last modified February 25 18:54 EST 2024. Contains 370332 sequences. (Running on oeis4.)