

A026472


{3, 7} together with the numbers congruent to {1, 2} mod 12.


3



1, 2, 3, 7, 13, 14, 25, 26, 37, 38, 49, 50, 61, 62, 73, 74, 85, 86, 97, 98, 109, 110, 121, 122, 133, 134, 145, 146, 157, 158, 169, 170, 181, 182, 193, 194, 205, 206, 217, 218, 229, 230, 241, 242, 253, 254, 265, 266, 277, 278, 289, 290, 301, 302, 313, 314
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,2


COMMENTS

The old definition of this sequence was "a(n) = least positive integer > a(n1) and not equal to a(i)+a(j)+a(k) for 1<=i<=j<=k<=n". However, Ralf Stephan observes that this does not fit the terms shown. The present definition (due to Stephan) has been adopted as a temporary solution.  N. J. A. Sloane, Nov 24 2004
Regarding the old definition, see Comments at A047239.  Clark Kimberling, Oct 09 2019


LINKS

Clark Kimberling, Table of n, a(n) for n = 1..10000
Index entries for linear recurrences with constant coefficients, signature (1,1,1).


FORMULA

From Colin Barker, Oct 10 2019: (Start)
G.f.: x*(1 + x + 3*x^3 + 5*x^4  3*x^5 + 5*x^6) / ((1  x)^2*(1 + x)).
a(n) = a(n1) + a(n2)  a(n3) for n>6.
a(n) = (39/2)  (5*(1)^n)/2 + 6*n for n>4.
(End)


MATHEMATICA

p = {1, 2, 3, 7}; r = 12 Range[200]; Union[p, 1 + r, 2 + r] (* Clark Kimberling, Oct 10 2019 *)


PROG

(PARI) Vec(x*(1 + x + 3*x^3 + 5*x^4  3*x^5 + 5*x^6) / ((1  x)^2*(1 + x)) + O(x^40)) \\ Colin Barker, Oct 20 2019


CROSSREFS

Cf. A026476, A026474.
Sequence in context: A081256 A084955 A273056 * A286176 A318401 A322703
Adjacent sequences: A026469 A026470 A026471 * A026473 A026474 A026475


KEYWORD

nonn


AUTHOR

Clark Kimberling


EXTENSIONS

More terms


STATUS

approved



