The On-Line Encyclopedia of Integer Sequences (OEIS)

A088849 revision #3

A088849

Number of prime factors, with multiplicity, of numbers that can be expressed as the sum of two distinct 4th powers in exactly two distinct ways.

4, 4, 4, 4, 3, 4, 4, 4, 6, 4, 5, 6, 4, 4, 7, 5, 7, 4, 3, 5, 6, 5, 6, 5, 6, 4, 5, 5, 6, 5, 4, 5, 4, 4, 6, 6, 6, 6, 6, 6, 5, 5, 6, 5, 6, 6, 7, 5, 7, 5, 6, 4, 5, 6, 6, 6, 5, 6, 5, 6, 4, 6, 4, 7, 6, 7, 5, 4, 5, 4, 5, 4, 6, 6, 5, 6, 6, 6, 5, 7, 4, 5, 6, 4, 6, 5, 6, 4, 5, 8, 9, 5, 5, 6, 6, 5, 3, 5, 8, 5, 7, 5, 7, 6, 4

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

OFFSET

1,1

LINKS

Table of n, a(n) for n=1..105.

D. J. Bernstein, List of 516 primitive solutions p^4 + q^4 = r^4 + s^4

Cino Hilliard, p,q,r,s and evaluation of the Bernstein data

Cino Hilliard, Evaluation of the Bernstein data only

FORMULA

Bigomega(n) for n = a^4+b^4 = c^4+d^4 for distinct a, b, c, d. n=635318657, 3262811042, .., 680914892583617, .., 962608047985759418078417

EXAMPLE

The 16th entry in the Bernstein Evaluation =

680914892583617 = 17*17*89*61657*429361 = 5 factors. 5 is the 16th entry in the

sequence.

PROG

(PARI) \ begin a new session and (back slash)r x4data.txt (evaluated Bernstein data) \ to the gp session. This will allow using %1 as the initial value. bigomegax4py42(n) = { for (i = 1, n, x = eval( Str("%", i) ); y=bigomega(x); print(y", ") ) }

CROSSREFS

Cf. A003824.

Sequence in context: A147563 A136213 A088848 * A251539 A123932 A010709

Adjacent sequences: A088846 A088847 A088848 * A088850 A088851 A088852

KEYWORD

fini,nonn,new

AUTHOR

Cino Hilliard (hillcino368(AT)hotmail.com), Nov 24 2003

STATUS

approved