A336189 The perfect square integer sum of a square block of integers, with 1 at the top-left corner, on a diagonally numbered 2D board.

1, 48841, 151757761, 7148452448281, 22211509021338121, 1046258952151234702321, 3250912043200499426917081, 153132136343696050161247674961, 475808694603918281112156880430641

Offset: 1

Author

Scott R. Shannon and Eric Angelini, Jul 11 2020

Keywords

• nonn
• more

Comments

See A336186 for the corresponding square edge length and an explanation of the sequence. Note that the currently known terms all end in 1.

Examples

			a(1) = 1 = 1^2.
a(2) = 48841 = 221^2.
a(3) = 151757761 = 12319^2.
a(4) = 7148452448281 = 2673659^2.
a(5) = 22211509021338121 = 149035261^2.
a(6) = 1046258952151234702321 = 32345926361^2.
a(7) = 3250912043200499426917081 = 1803028575259^2.
a(8) = 153132136343696050161247674961 = 391321014441719^2.
a(9) = 475808694603918281112156880430641 = 21813039554448121^2.
See A336186 for a diagram of the 2D board and examples.
		

Links

• Eric Angelini, Prime squares and square squares, personal blog "Cinquante signes", Jun. 29, 2020.
• Eric Angelini, Prime squares and square squares, personal blog "Cinquante signes", Jun. 29, 2020. [Cached copy]

Crossrefs

Cf. A336186, A185505, A000290, A000124, A000217.