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A341983 Number of ways to write n as an ordered sum of 4 primes (counting 1 as a prime). 9
1, 4, 10, 16, 23, 28, 38, 44, 55, 52, 62, 60, 84, 80, 106, 88, 123, 108, 160, 128, 184, 136, 214, 168, 261, 172, 270, 168, 304, 204, 352, 200, 382, 232, 442, 264, 470, 232, 502, 268, 557, 300, 608, 292, 672, 340, 722, 372, 789, 356, 856, 396, 900, 432, 968, 380, 1024, 432 (list; graph; refs; listen; history; text; internal format)
OFFSET

4,2

LINKS

Alois P. Heinz, Table of n, a(n) for n = 4..10000

FORMULA

G.f.: ( x + Sum_{k>=1} x^prime(k) )^4.

MAPLE

b:= proc(n) option remember; series(`if`(n=0, 1, x*add(

      `if`(j=1 or isprime(j), b(n-j), 0), j=1..n)), x, 5)

    end:

a:= n-> coeff(b(n), x, 4):

seq(a(n), n=4..61);  # Alois P. Heinz, Feb 24 2021

MATHEMATICA

nmax = 61; CoefficientList[Series[(x + Sum[x^Prime[k], {k, 1, nmax}])^4, {x, 0, nmax}], x] // Drop[#, 4] &

CROSSREFS

Cf. A008578, A280917, A283762, A340960, A341947, A341975, A341982, A341984.

Sequence in context: A215032 A294980 A310534 * A184527 A246297 A049881

Adjacent sequences:  A341980 A341981 A341982 * A341984 A341985 A341986

KEYWORD

nonn

AUTHOR

Ilya Gutkovskiy, Feb 24 2021

STATUS

approved

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Last modified December 4 09:10 EST 2021. Contains 349484 sequences. (Running on oeis4.)