1867357583296451

This number is a prime.

                                                           186735 7583296451

Largest known prime partial sum of of number of n-node unrooted quartic trees, equivalently partial sums of number of n-carbon alkanes C(n)H(2n+2) ignoring stereoisomers. It is the 43rd such partial sum: 1 + 1 + 1 + 1 + 2 + 3 + 5 + 9 + 18 + 35 + 75 + 159 + 355 + 802 + 1858 + 4347 + 10359 + 24894 + 60523 + 148284 + 366319 + 910726 + 2278658 + 5731580 + 14490245 + 36797588 + 93839412 + 240215803 + 617105614 + 1590507121 + 4111846763 + 10660307791 + 27711253769 + 72214088660 + 188626236139 + 493782952902 + 1295297588128 + 3404490780161 + 8964747474595 + 23647478933969 + 62481801147341 + 165351455535782 + 438242894769226 + 1163169707886427 = 1867357583296451 is prime [Post]