WON TOPIC 80

World!Of Numbers		WON plate 80 \|
Some curious polygonals The 44^th enneagonal (9-sided polygonal) number is 6666 ! (Sloane's A028992) The 26^th decagonal (10-sided polygonal) number is 2626 ! (Sloane's A001107) The 74^th heptagonal (7-sided polygonal : n[5n-3]) number is 13579 (Sloane's A014637), a number with its odd digits in ascending order ! Variations on the theme : %N n^2 has digits in ascending order. under A028819 %N Squares with digits in ascending order. under A028820 %N n^2 has digits in descending order. under A028821 %N Squares with digits in descending order. under A028822 %N Primes with digits in ascending order. under A028864 %N Primes with digits in descending order. under A028867 %N Primes that when squared gives numbers with digits in ascending order. under A028865 %N Primes that when squared gives numbers with digits in descending order. under A028868 %N Squares of primes with digits in ascending order. under A028866 %N Squares of primes with digits in descending order. under A028869
A000080 Prime Curios! Prime Puzzle Wikipedia 80 Le Nombre 80 Numberland 80

%N n^2 has digits in ascending order. under A028819
%N Squares with digits in ascending order. under A028820
%N n^2 has digits in descending order. under A028821
%N Squares with digits in descending order. under A028822
%N Primes with digits in ascending order. under A028864
%N Primes with digits in descending order. under A028867
%N Primes that when squared gives numbers with digits in ascending order. under A028865
%N Primes that when squared gives numbers with digits in descending order. under A028868
%N Squares of primes with digits in ascending order. under A028866
%N Squares of primes with digits in descending order. under A028869