login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A279372 Expansion of (Sum_{k>=1} x^(prime(k)^2))^2. 0
0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 2, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 2, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,14

COMMENTS

Number of ordered ways of writing n as the sum of two squares of primes (A001248).

LINKS

Table of n, a(n) for n=0..98.

Index entries for sequences related to sums of squares

FORMULA

G.f.: (Sum_{k>=1} x^(prime(k)^2))^2.

a(n) = Sum_{i=1..n} A302048(i)*A302048(n-i). - Ridouane Oudra, Nov 21 2020

EXAMPLE

a(13) = 2 because we have [4, 9] and [9, 4].

MATHEMATICA

nmax = 125; CoefficientList[Series[(Sum[x^Prime[k]^2, {k, 1, nmax}])^2, {x, 0, nmax}], x]

CROSSREFS

Cf. A001248, A063725, A073610, A302048.

Sequence in context: A230686 A341001 A221836 * A086077 A178408 A073345

Adjacent sequences:  A279369 A279370 A279371 * A279373 A279374 A279375

KEYWORD

nonn

AUTHOR

Ilya Gutkovskiy, Dec 24 2016

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified May 25 02:55 EDT 2022. Contains 354047 sequences. (Running on oeis4.)