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A339630 a(n) is the first number k such that there are exactly n ways to write 6*k = p + q with p a lesser twin prime (A001359) and q a greater twin prime (A006512), or 0 if there is no such k. 2
1, 2, 3, 4, 8, 20, 19, 80, 40, 90, 48, 270, 35, 50, 117, 140, 110, 644, 215, 714, 222, 430, 345, 350, 315, 850, 390, 930, 620, 1110, 602, 1040, 385, 2290, 590, 780, 798, 910, 735, 990, 1020, 1700, 700, 770, 595, 1760, 950, 3380, 875, 5660, 1330, 1120, 975, 5970, 1085, 2990, 1400, 3980, 1815, 4570 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

If n is odd, a(n)/2 (if nonzero) is in A002822.

LINKS

Robert Israel, Table of n, a(n) for n = 0..1330

FORMULA

A339625(a(n)) = n if a(n) > 0.

EXAMPLE

a(4) = 8 because 6*8 = 48 can be written as p+q in exactly 4 ways: 48 = 5 + 43 = 17 + 31 = 29 + 19 = 41 + 7, and no smaller number has this property.

MAPLE

# given list A339625

T:= Array(0..max(A339625)):

for n from 1 to nops(A339625) do

  if T[A339625[n]] = 0 then T[A339625[n]]:= n fi

od:

for k from 1 while T[k] <> 0 do od:

seq(T[i], i=0..k-1);

CROSSREFS

Cf. A001359, A002822, A006512, A339625.

Sequence in context: A215897 A276673 A282815 * A105055 A108506 A129284

Adjacent sequences:  A339627 A339628 A339629 * A339631 A339632 A339633

KEYWORD

nonn

AUTHOR

J. M. Bergot and Robert Israel, Dec 10 2020

STATUS

approved

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Last modified May 12 15:33 EDT 2021. Contains 343825 sequences. (Running on oeis4.)