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A218491 Number of ways that prime(n) can be represented as the sum of four nonzero squares. 1
0, 0, 0, 1, 0, 1, 0, 1, 1, 0, 2, 2, 0, 2, 2, 1, 1, 2, 3, 2, 3, 3, 2, 1, 4, 1, 5, 2, 3, 2, 5, 2, 3, 4, 2, 5, 6, 6, 5, 3, 3, 5, 5, 6, 4, 7, 5, 9, 5, 7, 4, 6, 6, 5, 5, 7, 4, 9, 8, 4, 9, 6, 10, 8, 10, 7, 9, 9, 7, 9, 8, 9, 13, 10, 10, 11, 7, 13, 7, 10, 8, 11, 10, 13 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,11

COMMENTS

a(pi(A213721(n))) = n, where pi(n) is the prime counting function.

LINKS

Arkadiusz Wesolowski, Table of n, a(n) for n = 1..1000

Index entries for sequences related to sums of squares

EXAMPLE

a(11) = 2 because prime(11) = 31 = 2*1 + 4 + 25 = 4 + 3*9.

MATHEMATICA

Table[Count[PowersRepresentations[Prime[n], 4, 2], _?(Min[#] > 0 &)], {n, 84}]

CROSSREFS

Cf. A025428, A213721.

Sequence in context: A307757 A215283 A066518 * A111165 A349812 A029321

Adjacent sequences:  A218488 A218489 A218490 * A218492 A218493 A218494

KEYWORD

nonn

AUTHOR

Arkadiusz Wesolowski, Nov 02 2012

STATUS

approved

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Last modified January 20 07:44 EST 2022. Contains 350467 sequences. (Running on oeis4.)