the positive integers are arranged in the pattern illustrated below if this pattern continues indefinitely, what is the number immediately above 39863?
1 2 5 10 17 26
3 4 7 12 19 28
6 8 9 14 21 30
11 13 15 16 23 32
18 20 22 24 25 34
27 29 31 33 35 36
Source: https://www.algebra.com/algebra/homework/word/misc/Miscellaneous_Word_Problems.faq.question.1131667.html
Let row = n
Let column = k
Formula:
T(n,k)=(k−1)2+2n−1n≤kT(n,k)=(n−1)2+2kn>k
Source: http://oeis.org/search?q=a185725&sort=&language=english
1. √39863=199.657…nmin=199nmax=200
T(200,k)=(200−1)2+2kn>k39863=1992+2k2k=39863−19922k=262k=131
The number immediately above:
T(199,131)=(199−1)2+2⋅131n>kT(199,131)=1982+2⋅131T(199,131)=39466