A115177 - OEIS

%I #14 Mar 09 2018 02:50:00

%S 690,861,915,929,1201,1319,1451,1538,1578,1803,1965,2104,2427,2532,

%T 2573,2671,2680,2734,2769,2965,3001,3154,3175,3255,3259,3260,3336,

%U 3434,3476,3603,3628,3670,3805,3840,3847,3898,3903,3953,4050,4128

%N Positive numbers that are not the sum of a triangular number, a nonnegative cube and a positive Fibonacci number.

%C There are 225943534 such numbers up to 10^9, the last one in this range being 999999997.

%H Robert Israel, <a href="/A115177/b115177.txt">Table of n, a(n) for n = 1..10000</a>

%p N:=10000: # to get all terms <= N

%p T:= [seq(t*(t+1)/2, t=0..floor((sqrt(1+8*N)-1)/2))]:

%p C:= [seq(t^3, t=0..floor(N^(1/3)))]:

%p F:= [seq(combinat:-fibonacci(t), t=1..floor(log[(sqrt(5)+1)/2](N*sqrt(5))))]:

%p CF:= select(`<=`,{seq(seq(c+f, c=C),f=F)},N):

%p sort(convert({$1..N} minus {seq(seq(t+cf,t=T),cf=CF)}, list)); # _Robert Israel_, Mar 08 2018

%Y Cf. A115171, A115172, A115173, A115174, A115175, A115176.

%K nonn

%O 1,1

%A _Giovanni Resta_, Jan 15 2006

%E Name clarified by _Altug Alkan_, May 02 2016