A193244 - OEIS

A193244

Numbers that are the sum of three biquadrates (fourth powers) in more than one way.

16562, 28593, 35378, 43218, 54977, 94178, 106353, 122018, 134162, 137633, 149058, 181202, 195122, 198497, 235298, 235553, 264113, 264992, 300833, 318402, 324818, 364658, 384833, 439922, 457488, 462722, 514098, 522242, 566048, 611618, 624962

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OFFSET

1,1

COMMENTS

Erroneous version of A309762. - Ilya Gutkovskiy, Aug 15 2019

A subsequence of A003337. Lists the indices such that A193243(n) > 1.

LINKS

Table of n, a(n) for n=1..31.

EXAMPLE

a(1) = 16562 = 1^4 + 9^4 + 10^4 = 5^4 + 6^4 + 11^4, and this is the least number having two such decompositions.

PROG

(PARI) is_A000404(n)={ for( i=1, #n=factor(n)~%4, n[1, i]==3 & n[2, i]%2 & return); n & ( vecmin(n[1, ])==1 || (n[1, 1]==2 & n[2, 1]%2))} \\ M. F. Hasler, Feb 07 2009

(PARI) for(n=1, 9e9, is_A000404(n) && A193243(n)>1 && print1(n", "))

CROSSREFS

Cf. A003337, A193243, A047714, A085559, A122540, A123075.

Sequence in context: A253759 A091089 A109028 * A240901 A234894 A283028

Adjacent sequences: A193241 A193242 A193243 * A193245 A193246 A193247

KEYWORD

nonn

AUTHOR

M. F. Hasler, Jan 01 2013

STATUS

approved