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A083214 Numbers n for which 3 | p(n), where p(n) = A000041(n) is the n-th partition number. 6
3, 7, 9, 10, 14, 16, 17, 20, 21, 22, 24, 26, 30, 32, 33, 35, 39, 40, 41, 43, 46, 48, 51, 52, 53, 57, 61, 63, 68, 70, 71, 75, 80, 88, 97, 102, 104, 106, 107, 111, 115, 124, 125, 129, 133, 138, 142, 147, 151, 160, 162, 163, 164, 169, 173, 178, 180, 181, 189, 191, 193 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..61.

FORMULA

Conjecture : a(n)=3n+o(n). - Benoit Cloitre, Oct 06 2005

A000041(a(n)) = A087183(n). - Zak Seidov, Apr 03 2007

EXAMPLE

A000041(7)=15=0 mod 3.

MATHEMATICA

Select[Range[250], Mod[PartitionsP[ # ], 3]==0&] - Zak Seidov, Apr 03 2007

PROG

(PARI) { v=[1, 1, 2, 3, 5, 7, 11, 15, 22, 30, 42, 56, 77, 101, 135, 176, 231, 297, 385, 490, 627, 792, 1002, 1255, 1575, 1958, 2436, 3010, 3718, 4565, 5604, 6842, 8349, 10143, 12310, 14883, 17977, 21637, 26015, 31185, 37338, 44583, 53174, 63261, 75175, 89134]; for (i=2, length(v)-1, if (v[i]%3==0, print1(i-1", "))) }

(PARI) for(n=1, 300, if(polcoeff(1/eta(x)+O(x^(n+1)), n)%3==0, print1(n, ", "))) \\ Cloitre

(PARI) is(n)=numbpart(n)%3==0 \\ Charles R Greathouse IV, Apr 08 2015

CROSSREFS

Cf. A000041, A087183, A243935.

Sequence in context: A082575 A284526 A294571 * A091210 A276492 A023992

Adjacent sequences:  A083211 A083212 A083213 * A083215 A083216 A083217

KEYWORD

nonn

AUTHOR

Jon Perry, Jun 01 2003

EXTENSIONS

More terms from Benoit Cloitre, Oct 06 2005

STATUS

approved

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Last modified May 24 17:39 EDT 2019. Contains 323534 sequences. (Running on oeis4.)