login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A292225
Row sums of irregular triangle A292224. a(n) gives the total number of admissible tuples starting with 0 in the interval [0, 1, ..., n-1].
1
1, 1, 2, 2, 3, 3, 6, 6, 10, 10, 14, 14, 28, 28, 41, 41, 57, 57, 105, 105, 160, 160, 210, 210, 383, 383, 531, 531, 678, 678, 1343, 1343, 1923, 1923, 2482, 2482, 4402, 4402, 5849, 5849, 7824, 7824, 14064, 14064, 18292, 18292, 23981, 23981, 39745, 39745, 57307, 57307, 71639, 71639, 117846, 117846
OFFSET
1,3
COMMENTS
This sequence is given in column 2 of Table 2, p. 27, of the Engelsma link.
See A292224 for the reason for the repetitions for n = 2*k+1 and n = 2*(k+1) for k >= 0, the definition of "admissible", references, and examples of these admissible k-tuples for n = 1..10 (with k = 1, 2, ..., A023193(n)).
LINKS
Thomas J. Engelsma, Permissible Patterns of Primes, September 2009, Table 2, p. 27.
FORMULA
a(n) = Sum_{k=1..A023193(n)} A292224(n, k), for n >= 1.
CROSSREFS
Sequence in context: A032155 A116932 A240579 * A238786 A238547 A325681
KEYWORD
nonn
AUTHOR
Wolfdieter Lang, Oct 09 2017
EXTENSIONS
Terms a(27) .. a(56) from Engelsma's Table 2 (there are also a(57)..a(62) given but a(62) should be 364545 if a(61) = 364545 is correct). - Wolfdieter Lang, Oct 17 2017
STATUS
approved