A249724 Numbers k such that on row k of Pascal's triangle there is no multiple of 9 which would be less than any (potential) multiple of 4 on the same row.

0, 1, 2, 3, 4, 5, 6, 7, 8, 11, 12, 14, 16, 17, 20, 22, 23, 24, 25, 26, 28, 30, 32, 33, 34, 35, 36, 38, 40, 41, 42, 44, 48, 49, 50, 51, 52, 53, 56, 57, 58, 60, 61, 62, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 76, 77, 78, 80, 84, 86, 88, 89, 92, 94, 96, 97, 98, 100, 101, 102, 104, 105, 106, 107, 108, 110, 112, 113, 114, 115, 116, 120, 121

Offset

1,3

Comments

Disjoint union of {0} and the following sequences: A048278 (gives 7 other cases where there are neither multiples of 4 nor 9 on row k), A249722 (rows where a multiple of 4 is found before a multiple of 9), A249726 (cases where the least term on row k which is a multiple of 4 is also a multiple of 9, and vice versa, i.e., such a term a multiple of 36).

If A249717(k) < 3 then k is included in this sequence. This is a sufficient but not necessary condition, e.g., A249717(25) = 5, but 25 is also included in this sequence.

Links

Antti Karttunen, Table of n, a(n) for n = 1..23590

Prog

(PARI)
A249724list(upto_n) = { my(i=0, n=0, dont_print=0); while(i<upto_n, for(k=0, n\2, if(!(binomial(n, k)%4), i++; write("b249724.txt", i, " ", n); dont_print=1; break, if(!(binomial(n, k)%9), dont_print=1; break))); if(!dont_print, i++; write("b249724.txt", i, " ", n), dont_print=0); n++); } \\ Ugly code.

Crossrefs

Complement: A249723.

Cf. A007318, A052955, A249441, A249695, A249717, A048278, A048645, A051382, A249722, A249726.

Sequence in context: A365127 A093515 A350242 * A084369 A167211 A362095

Adjacent sequences: A249721 A249722 A249723 * A249725 A249726 A249727

Keyword

nonn

Author

Antti Karttunen, Nov 04 2014

Status

approved