Phi(n): A005728 *
phi(n): see totient function phi(n) (A000010 )
pi(10^n): A006880
pi(x), number of primes <= x: A000720 *
Pi, continued cotangent for: A002667 *
Pi, continued fraction for: A001203 *, A033089
Pi, convergents to: A002485 */A002486 *
Pi, decimal expansion of: A000796 *
Pi, see also: A007514 , A006941 , A000796 *, A001355 , A001203 , A007523 , A005042 , A002667 , A006524 , A002161 , A007541 , A001467 , A001466 , A002388 , A006934 , A005149 , A005148
Pi, strings of digits in: ( 1) A014976 , A050201 , A050202 , A083598 , A083599 , A083600 , A083601
Pi, strings of digits in: ( 2) A053745 , A050208 , A050209 , A083602 , A083603 , A083604 , A083605
Pi, strings of digits in: ( 3) A053746 , A050215 , A083606 , A083607 , A083608 , A083609
Pi, strings of digits in: ( 4) A053747 , A050222 , A083610 , A083611 , A083612 , A083613 , A083614
Pi, strings of digits in: ( 5) A053748 , A050230 , A083615 , A083616 , A083617 , A083618 , A083619
Pi, strings of digits in: ( 6) A053749 , A050238 , A083620 , A083621 , A083622 , A083623 , A083624
Pi, strings of digits in: ( 7) A053750 , A050245 , A083625 , A083626 , A083627 , A083628 , A083629 , A083630
Pi, strings of digits in: ( 8) A053751 , A050254 , A083631 , A083632 , A083633 , A083634 , A083635 , A083636
Pi, strings of digits in: ( 9) A053752 , A050263 , A083637 , A083638 , A083639 , A083640 , A083641
Pi, strings of digits in: (10) A053753 , A050272 , A083642 , A083643 , A083644 , A083645 , A083646
piano keyboard: A059620 *, A079731 , A060106 , A060107 , A081031 , A081032
picture-perfect numbers: A069942
pieces: see also under partitions
Pierce expansions: A006275 , A006276 , A006283 , A006284
Pierpont primes: see primes, Pierpont
Pisano numbers: see Pisano periods
Pisano periods: A001175 *
Pisot sequences, definition: A008776 *
Pisot sequences, warning about recurrences for: A010925
Pisot sequences: ( 1) A000051 A000079 A000244 A000302 A000351 A000400 A000420 A001018 A001019 A001519 A004171 A007283
Pisot sequences: ( 2) A007484 A007699 A008776 A009056 A010900 A010901 A010902 A010903 A010904 A010905 A010906 A010907
Pisot sequences: ( 3) A010908 A010909 A010910 A010911 A010912 A010913 A010914 A010915 A010916 A010917 A010919 A010920
Pisot sequences: ( 4) A010922 A010924 A010925 A011557 A014001 A014002 A014003 A014004 A014005 A014006 A014007 A014008
Pisot sequences: ( 5) A018910 A018914 A018920 A019492 A020695 A020696 A020698 A020701 A020702 A020704 A020705 A020706
Pisot sequences: ( 6) A020707 A020708 A020709 A020710 A020711 A020712 A020713 A020714 A020715 A020716 A020717 A020718
Pisot sequences: ( 7) A020719 A020720 A020721 A020722 A020723 A020727 A020728 A020729 A020730 A020732 A020734 A020735
Pisot sequences: ( 8) A020736 A020737 A020739 A020741 A020742 A020743 A020744 A020745 A020746 A020747 A020748 A020749
Pisot sequences: ( 9) A020750 A020751 A020752 A021000 A021001 A021004 A021006 A021008 A021011 A021013 A021014 A048575
Pisot sequences: (10) A048576 A048577 A048578 A048579 A048580 A048581 A048582 A048583 A048584 A048585 A048586 A048587
Pisot sequences: (11) A048588 A048589 A048590 A048591 A048592 A048624 A048625 A048626 A051016 A051017
planar graphs: see graphs, planar
planar vs plane: some authors make a distinction between "plane", meaning embedded in the plane with a distinguished exterior region, and "planar", meaning embedded in the sphere (with no distinguished region)
Planck's constant: A003676
plus perfect numbers: A005188 *