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!)
A161078 Number of partitions of n into primes or 1 where every part appears at least 3 times. 1
0, 0, 1, 1, 1, 2, 1, 2, 3, 3, 3, 6, 5, 6, 10, 8, 9, 14, 13, 16, 21, 19, 23, 30, 31, 34, 42, 44, 49, 60, 61, 68, 83, 85, 96, 111, 115, 129, 149, 158, 173, 196, 210, 229, 260, 275, 301, 339, 359, 392, 436, 462, 505, 559, 594, 645, 708, 755, 817, 895, 952, 1026, 1123, 1194, 1287 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,6

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..1000

FORMULA

G.f.: -1+(1+x^3/(1-x))*product[1+x^{3*p(j)}/(1-x^{p(j)}, j=1..infinity], where p(j) is the j-th prime. - Emeric Deutsch, Jun 27 2009

EXAMPLE

a(12)=6 because we have 3333, 333111, 2^6, 22221111, 2221^6, and 1^(12). - Emeric Deutsch, Jun 27 2009

MAPLE

g := -1+(1+x^3/(1-x))*(product(1+x^(3*ithprime(j))/(1-x^ithprime(j)), j = 1 .. 20)): gser := series(g, x = 0, 75): seq(coeff(gser, x, n), n = 2 .. 65); # Emeric Deutsch, Jun 27 2009

CROSSREFS

Sequence in context: A161308 A161242 A161027 * A161294 A161269 A100405

Adjacent sequences:  A161075 A161076 A161077 * A161079 A161080 A161081

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jun 02 2009

EXTENSIONS

Definition edited to "primes or 1" by R. H. Hardin, Jun 22 2009

STATUS

approved

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified January 20 06:12 EST 2022. Contains 350467 sequences. (Running on oeis4.)